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RD57  .N52  1 906       Surgical  Pathology : 


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SURGICAL  PATHOLOGY 


SYLLABUS, 


BY 


EDWARD    H.   NICHOLS,   M.D. 


Copyright,  igo6,  by  Edward  H.  Nichols,  M.D. 


PRINTED    BY 

J.  L.  FAIRBANKS  &  COMPANY 

u  and  IS  Franklin  Street 
BOSTON 


SURGICAL  PATHOLOGY 


SYLLABUS, 


BY 


EDWARD    H.    NICHOLS,    M.D. 


Copyright,  1906,  by  Edward  H.  Nichols,  M.D. 


^  PRINTED     BY 

J.   L.    FAIRBANKS   &  COMPANY 

II  and  15  Fraiiklia  Street 

BOSTON 


/•"  ''6 


SURGICAL    PATHOLOGY. 


SYLLABUS, 


EDWARD   H.    NICHOLS,   M.D. 


REPAIR    OF   TISSUES. 

I.  Wounds  :  A  wound  (trauma)  is  a  break  of  the  soft  tissues 
of  the  body  caused  by  violence.  A  wound  may  involve  the  skin 
(cutaneous)  or  only  the  tissues  beneath  the  skin  (subcutaneous). 

Classification  :  Wounds  are  classified  by  their  gross  appearance, 
which  varies  according  to  the  manner  in  which  the  injury  is  pro- 
duced ;  hence  incised,  punctured,  contused,  and  lacerated  wounds. 
In  incised  and  punctured  wounds  the  edges  of  the  wound  gener- 
ally can  be  approximated  easily  ;  in  contused  and  lacerated  wounds 
there  may  be  extensive  destruction  of  the  surface  tissues. 

Complications :  Various  complications  foUovv^  wounds  of  soft 
tissues.  These  complications  may  manifest  themselves  at  once, 
or  after  a  variable  length  of  time,  i.e.,  may  be  immediate  or 
secondary. 

I.     Immediate  complications. 

(a.)  Haemorrhage.  The  character  of  the  bleeding,  depends 
upon  the  character,  size,  and  location  of  the  divided  vessels, 
hence  arterial,  venous,  capillary,  or  a  combination. 

(/;.)  Division  of  muscles  or  tendons,  resulting  in  a  mechani- 
cal loss  of  power  in  the  injured  muscles. 

(r.)  Division  of  nerves,  resulting  in  a  loss  of  power  in  the 
muscles  supplied  by  the  injured  nerve. 

(^.)  Penetration  of  viscera,  the  results  varying  in  accordance 
with  the  character  of  the  organ  injured.  Emphysema  iiiay  follow 
injury  of  the  lung.  If  hollow  abdominal  vicera  are  wounded,  ex- 
travasation of  their  contents  and  peritonitis  may  occur.  Wounds 
of  solid  viscera  may  cause  serious  internal  haemorrhage. 

I 


2.  Secondary  complications  are  due  chiefly  to  infection  of 
wounded  tissues  by  pathogenic  microorganisms.  If  infection  oc- 
cur the  microorganisms  may  multiply  in  the  wounded  tissues, 
produce  a  toxin,  and  cause  various  suppurative  phenomena. 
They  may  cause  a  solution  of  subcutaneous  tissue  and  an  abscess, 
or  they  and  their  products  may  extend  along  the  lymphatic  vessels 
and  produce  lymphangitis  and  diffuse  suppuration  (i)hlegmon), 
or  the  infection  may  extend  to  adjacent  blood  vessels  and  cause 
coagulation  of  the  blood  (thrombosis),  which  may  be  followed  by 
embolism  and  py?emia ;  or  a  general  infection,  with  toxaemia  and 
septicaemia,  may  occur. 

Aseptic  and  septic  xvoinuls  :  If  a  wound  heals  without  infection 
by  pathogenic  microorganisms  it  is  said  to  be  aseptic  ;  if  micro- 
organisms are  present  it  is  septic.  Wounds  seldom  heal  asepti- 
cally  unless  treated  surgically. 

Healing  of  wounds :  In  every  wound  the  immediate  result  of 
the  injury  is  a  destruction  of  tissue.  This  destruction  of  tissue  is 
followed  immediately  by  the  formation  of  exudation  at  the  point 
of  injury.  In  aseptic  wounds  the  amount  of  exudate  is  propor- 
tional to  the  amount  of  injury,  i.e.,  to  the  extent  of  the  wound. 
In  septic  wounds  the  amount  of  exudate  is  proportional  to  the 
amount  of  injury  caused  by  the  wound  itself,  and  further  to  the 
amount  of  injury  due  to  the  action  of  the  toxin  produced  by  the 
microorganisms. 

Following  the  exudate  come  certain  proliferative  changes,  con- 
fined chiefly  to  the  epithelium,  connective  tissue,  and  blood  ves- 
sels about  the  injured  area.  Connective  tissue  and  blood  vessels 
form  granulation  tissue,  which  ultimately  becomes  dense  scar 
tissue  and  replaces  the  tissue  that  has  been  destroyed. 

The  entire  process  of  exudation  and  formation  of  scar  tissue  is 
spoken  of  as  repair  of  wounds.  The  general  steps  of  the  process 
are  the  same,  whether  the  edges  of  the  wound  can  be  approxi- 
mated (incised  or  closed  wound)  or  whether  the  edges  cannot  be 
approximated  on  account  of  extensive  destruction  of  tissue  (lac- 
erated or  contused  or  open  wounds),  but  there  are  slight  differ- 
ences in  detail,  so  that  it  is  customary  to  describe  the  healing  of 
aseptic  closed  and  open  wounds  separately. 

Repair  of  aseptic  closed  wounds,  "  First  Intention "  .•  The 
process  is  seen  in  its  simplest  form  and  best  studied  in  experi- 
mental lesions  on  animals,  notably  the  ear  or  the  tongue  of  a 
rabbit.     The  immediate  result  of  the  injury  is  haemorrhage.     In 


3 


a  few  hours  the  interval  between  the  approximated  edges  is  filled 
with  an  exudate  of  leucocytes,  serum,  and  fibrin  with  some  red 
blood  corpuscles,  the  number  of  the  latter  depending  upon  the 
amount  of  haemorrhage  and  diapedesis.  The  adjacent  blood 
vessels  are  dilated.  The  exudate  extends  laterally  for  a  consider- 
able distance  into  adjacent  tissues,  and  on  the  surface  coagulates 
to  form  a  crust,  or  "  scab." 

After  a  few  hours,  proliferation  of  epithelium  and  connective 
tissue  adjacent  to  the  wound  begins,  .\djacent  epithelium  pro- 
liferates, mitotic  figures  appear,  and  new  epithelial  cells  begin  to 
extend  over  the  surface  of  the  exudate  beneath  the  scab.  The 
connective  tissue  cells  proliferate,  young  connective  tissue  cells, 
oval  or  polygonal,  appear,  and  extend  into  the  deep  exudate. 
At  the  same  time  loops  of  young  blood  vessels  are  formed  from 
adjacent  blood  vessels  and  project  into  the  exudate. 

This  process  continues  for  a  variable  time,  depending  upon  the 
size  of  the  wound,  the  character  of  the  tissue,  the  amount  of 
haemorrhage,  and  the  accuracy  of  approximation  of  the  edges, 
until  the  space  filled  by  inflammatory  exudate  is  filled  with  newly 
formed  loops  of  blood  vessels  and  young  connective  tissue  cells, 
"  granulation  tissue,"  while  the  surface  of  the  wound  is  covered 
by  proliferated  epithelium.  This  process  may  be  completed  in 
seven  days,  but  usually  takes  from  three  to  five  days  more.  As 
the  proliferation  advances,  the  exudate  diminishes,  and  in  experi- 
mental lesions  may  disappear  about  the  seventh  day. 

Finally  the  epithelium  is  completely  restored.  The  voung 
connective  tissue  cells  become  spindle-shaped,  with  oval  nuclei. 
Still  later,  intercellular  fibrillar  material  appears  between  the 
cells,  the  blood  vessels  disappear,  probably  on  account  of  pressure 
by  the  contractile  connective  tissue  fibres,  and  the  lost  tissue  is 
replaced  by  dense  scar  tissue,  in  which  are  few  or  no  blood 
vessels,  and  the  scar  is  covered  by  normal  epithelium.  The 
epithelium  generally  forms  a  thin  layer,  with  parallel  external  and 
deep  surfaces,  and  shows  but  little  tendency  to  form  papillce. 
Sometimes,  however,  the  epidermis  sends  long  processes  down 
into  the  scar,  or  islands  of  epithelial  cells  may  become  cut  off  in 
the  depths  of  the  wound.  The  entire  process  is  completed  in 
from  ten  days  to  two  weeks,  but  the  scar  tissue  continues  to  con- 
tract and  become  smaller  several  weeks,  or  even  months. 

In  human  wounds  the  process  is  the  same,  but  owing  to  the 
extent   of  the    wound    and    the  complex    anatomy  the    process 


appears  more  complicated.  The  edges  of  the  wound  never  are 
exactly  approximated.  The  line  of  incision  seldom  appears  sharply 
defined  microscopically,  probably  because  of  injury  due  to  manip- 
ulation during  the  operation.  The  inflammatory  exudate  extends 
to  a  considerable  extent  into  adjacent  tissues.  When  prolifera- 
tion begins  it  extends  to  a  considerable  extent  into  the  surround- 
ing tissues,  often  for  several  centimetres  on  either  side  of  the 
wound,  and  the  deep  line  of  incision  cannot  be  accurately  fol- 
lowed after  the  fourth  or  fifth  day.  The  different  layers  of  con- 
nective tissue,  fascia,  etc.,  take  part  in  the  proliferation  to  a 
varying  degree.  The  process  takes  longer  than  in  animals,  and 
areas  of  lymphoid  and  plasma  cells  appear.  In  places  small 
remnants  of  inflammatory  exudate  may  remain  after  the  greater 
portion  of  the  wound  shows  advanced  repair.  If  bits  of  fibrin 
remain,  many  giant  cells  appear.  In  human  wounds  the  process 
of  vascular  scar  formation  takes  about  ten  days,  the  time  varying 
somewhat  according  to  the  size  of  the  wound.  The  scar  con- 
tinues to  contract  and  become  less  and  less  vascular  for  some 
months,  or  even  for  a  year  or  more.  Sometimes  after  several 
months  microscopic  section  of  a  linear  wound,  which  has  healed 
by  first  intention,  may  fail  absolutely  to  show  any  appreciable 
histological  change,  or  at  most  may  show  a  thinning  of  the  epi- 
dermis along  the  line  of  incision,  even  although  a  white  scar  may 
be  obvious  to  the  eye. 

The  gross  appearances  correspond  to  the  described  histological 
process.  At  the  end  of  a  few  hours  the  edges  of  the  wound  are 
sealed  together  by  an  adhesive  layer  of  exudation,  yellow  or  red, 
if  there  has  been  much  haemorrhage.  In  24  to  48  hours  this 
adhesive  layer  becomes  hard  and  dry  on  the  surface,  and  forms  a 
crust  or  scab.  The  edges  of  the  wound  are  somewhat  swollen 
and  reddened  because  of  the  presence  of  exudate  and  dilated 
blood  vessels.  The  edges  also  are  slightly  hot  and  tender.  If 
the  edges  are  separated  there  is  relatively  little  bleeding,  since 
few  new  blood  vessels  are  formed,  and  the  tissues  appear  opaque 
and  gelatinous  from  necrosis  and  infiltration  with  exudate.  The 
space  between  the  edges  is  filled  with  opaque  exudate,  partly 
coagulated.  In  from  3  to  6  days,  if  the  crust  is  removed,  the 
surface  is  seen  to  be  covered  with  a  thin  layer  of  proliferated 
epithelium.  The  edges  can  be  separated  with  difficulty  and 
bleed  freely  if  separated,  the  haemorrhage  coming  from  the  gran- 
ulation tissue.     After  about  10   days  the  line    of  the  wound  is 


occupied  by  red  scar  tissue,  composed  of  spindle-celled  young 
connective  tissue,  in  which  are  numerous  young  blood  vessels. 
In  the  course  of  weeks  or  months  the  scar  becomes  white  and 
narrow  because  of  the  disappearance  of  blood  vessels  and  conver- 
sion of  young  connective  tissue  into  dense  connective  tissue. 

Repair  of  aseptic  open  wounds,  "  Second  Intttitioji  "  .•  Healing 
by  "  granulation."  As  a  result  of  injury  there  may  be  a  more  or 
less  extensive  destruction  of  the  superficial  and  underlying  tissues 
of  the  body,  producing  a  wound  so  extensive  that  the  skin  edges 
cannot  be  brought  together.  In  such  cases  the  details  of  the 
reparative  process  differ  from  the  process  in  closed  wounds, 
although  the  general  process  is  the  same. 

Almost  always  extensive  haemorrhage  occurs,  although  if  the 
wound  is  superficial  this  may  be  very  slight.  If  it -occurs  the 
blood  may  coagulate  upon  the  denuded  surface.  In  a  few  hours 
an  exudate  is  formed  upon  the  surface  of  the  wound,  consisting 
of  leucocytes,  serum,  and  fibrin,  and  the  exudate  also  extends  to 
a  considerable  depth  into  the  tissues  about  the  wound.  Adjacent 
blood  vessels  show  moderate  enlargement.  In  a  few  hours,  by 
coagulation  of  blood  and  formation  of  fibrin,  the  \vound  is 
covered  with  a  crust  or  scab. 

Proliferation  of  epithelium  and  connective  tissue  and  formation 
of  new  loops  of  blood  vessels  occur.  The  epithelium  about  the 
edge  of  the  wound  proliferates  and  grows  into  the  exudate  over 
the  surface  of  the  wound,  and  forms  a  film  of  proliferating  epi- 
thelial cells.  But  epithelium  has  a  limited  power  of  proliferation, 
and,  if  the  wound  is  extensive,  may  be  unable  to  cover  the  surface 
of  the  wound  for  many  weeks  or  months.  If  the  wound  remain 
open  the  epithelium  may  form  a  thickened,  rounded  layer  of  cells, 
depressed  at  the  advancing  edge. 

Proliferation  of  connective  tissue  cells,  with  formation  of  oval 
or  polygonal  epithelioid  or  young  connective  tissue  cells,  takes 
place  from  the  entire  surface  of  the  wound.  These  cells  grow 
into  and  replace  the  exudate. 

New  blood  vessels  arise  from  blood  vessels  near  the  wound, 
and  grow  into  the  exudate.  They  are  accompanied  by  the  young 
connective  tissue  cells. 

This  combination  of  young  blood  vessels  and  young  connective 
tissue  cells  forms  "  granulation  tissue."  Granulation  tissue  con- 
tinues to  form  until  the  wound  is  filled  to  the  level  of  the  skin. 
Often  the  granulation  tissue  rises  above  the  level  of  the  skin  if 


the  epithelial  growth  is  insufficient  to  cover  it  ("  exuberant 
granulation  "). 

So  long  as  the  surface  of  the  granulation  tissue  remains  un- 
covered by  epithelium  a  certain  amount  of  exudate  persists  and 
is  seen  between  the  meshes  of  the  granulation  tissue.  If  the 
reparative  process  is  prolonged,  because  of  the  size  of  the  wound 
or  from  other  causes,  lymphoid  and  plasma  cells  are  found  in  the 
tissue,  often  in  large  numbers.  If  the  process  is  subacute, 
eosinophils  may  be  numerous. 

If  the  wound  is  small  and  the  reparative  process  takes  but  a 
few  days  the  epithelium  proliferates,  grows  in  from  the  edge,  and 
covers  in  the  surface  of  the  wounds.  The  young  connective 
tissue  cells  become  spindle-shaped,  develop  intercellular  fibrillae, 
and  blood  vessels  become  less  numerous.  At  length  (ten  days 
in  experimental  lesions)  the  connective  tissue  becomes  dense 
connective  tissue,  while  blood  vessels  disappear.  In  that  case 
the  lost  tissue  is  replaced  by  a  mass  of  dense  connective  tissue 
covered  with  epithelium,  i.e.,  the  wound  is  replaced  by  a  con- 
tractile "scar."  This  process  is  seen  best  in  experimental 
lesions. 

On  the  other  hand,  if  the  wound  is  very  extensive  the  epi- 
thelium may  take  months  to  cover  over  the  surface  of  the  wound. 
In  that  case  the  wound  remains  open,  its  superficial  part  is  filled 
with  granulation  tissue,  in  which  is  exudate,  lymphoid,  and  plasma 
cells,  while  the  granulation  tissue  of  the  deeper  part  is  converted 
into  dense  connective  tissue,  whose  fibres  run  chiefly  parallel  to 
the  base  of  the  wound.  Such  a  wound  may  be  covered  with  a 
series  of  crusts,  or,  if  the  crusts  are  removed,  with  exudate. 

The  gross  appearances  correspond  to  these  histological  condi- 
tions. In  an  open  wound,  if  very  superficial,  haemorrhage  may 
not  be  visible,  ^..^,^,  "  barked  "  knuckles.  The  wounded  surface 
is  covered  in  a  few  hours  with  a  clear  or  yellowish  fluid,  which 
coagulates  in  a  short  time.  The  fluid  is  exudate  in  which  are 
more  or  less  leucocytes,  and  this  exudate  coagulates  and  forms  a 
thin  film  or  crust.  If  the  wound  is  deeper  more  or  less  haemor- 
rhage occurs.  Then  the  wound  in  a  few  hours  is  filled  with 
exudate  and  haemorrhage.  This  mixture  of  blood  and  exudate 
coagulates  and  forms  a  reddish  crust  or  scab.  In  two  or  three 
days  is  seen  extending  just  beneath  the  edges  of  the  crust  a  thin 
delicate  white  layer  (proliferated  epithelium).  If  the  crust  be 
removed  a  red,  bleeding  surface  is  exposed,  which  has  a  granular 


appearance,  hence  the  name  "  granulation  tissue."  The  promi- 
nences of  such  tissue  correspond  to  loops  of  blood  vessels  and 
their  accompanying  young  connective  tissue  cells.  The  removal 
of  such  an  adherent  crust  produces  injury  and  necrosis  of  the 
granulating  area  and  is  followed  by  a  slight  inflammation,  and  in 
that  way  delays  the  process  of  healing. 

If  the  wound  heal  promptly  the  epithelium  extends  over  the 
surface  of  the  wound  and  finally  covers  it  with  thin,  pearly  epi- 
dermis, the  underlying  granulation  tissue  becomes  fibrillated  and 
forms  a  somewhat  raised,  moderately  firm  red  scar.  After  weeks 
or  months  this  red  color  disappears  as  the  connective  tissue 
becomes  denser,  and  the  area  of  the  wound  is  marked  by  a  shin- 
ing white,  souiewhat  depressed  mass  of  dense  connective  tissue, 
covered  with  epithelium,  i.e.,  a  "scar."  The  scar  is  contractile, 
so  that  the  area  of  the  scar  is  always  less  than  that  of  the  original 
wound. 

If  the  wound  is  extremely  large,  or  the  process  of  healing  for 
any  reason  is  delayed,  the  wound  may  remain  open  for  weeks  or 
months.  In  that  case  the  edges  of  the  wound  are  covered  by  a 
thin  white  film  of  proliferating  epithelium,  which  still  is  unable  to 
close  the  wound.  The  rest  of  the  wound  is  filled  with  a  reddish, 
granular,  oozing  layer  of  granulation  tissue,  which  bleeds  easily. 
This  granulation  tissue  may  project  for  a  considerable  distance 
above  the  level  of  the  adjacent  skin,  "  exuberant  granulations." 
If  this  layer  of  granulation  tissue  is  scraped  off  a  layer  of  firm, 
pale,  slightly  vascular  connective  tissue  (layer  of  dense  cicatri- 
cial tissue)  is  seen.     This  layer  is  utilized  in  skin  grafting. 

Repair  by  '^  Third  Intension'':  Occasionally  in  wounds  in 
which  there  has  been  a  considerable  loss  of  tissue,  it  is  possible 
after  a  few  days  to  approximate  the  edges  of  the  wound  in  such 
a  way  as  to  convert  what  was  originally  an  open  wound  into  a 
closed  one.  In  such  cases  the  early  stages  of  repair  are  like 
those  of  the  open  wounds,  i.e.,  a  proliferation  of  epithelium  at 
the  edges  and  a  formation  of  granulation  tissue  at  the  bottom  of 
the  wound.  If  the  edges  then  are  closed  by  pressure  or  by  ap- 
proximation sutures,  surfaces  of  granulation  tissue,  covered  with 
a  varying  amount  of  exudate,  are  approximated  in  the  deeper 
part  of  the  wound,  while  at  the  surface  edges  of  proliferating 
epithelium  are  brought  together.  In  such  cases  under  favorable 
circumstances  the  open  wound  is  converted  into  a  closed  one,  the 
granulation  tissue  from  either  side  grows  into  and.  organizes  the 


8 


exudate,  the  epithelium  grows  over  and  closes  in  the  wound,  and 
the  later  stages  of  repair  are  like  those  of  a  wound  which  is  a 
closed  one  from  the  beginning. 

Inftcted  wounds :  Closed  or  open  wounds  may  become  infected 
by  various  pathogenic  microorganisms,  either  at  the  time  the 
wound  is  made  or  at  any  later  time  before  the  process  of  healing 
is  completed.  If  the  wound  is  accidental  it  may  be  infected  at 
the  time  it  is  produced  ;  if  the  wound  is  an  operative  one  infec- 
tion may  arise  from  surgically  unclean  instruments,  sponges, 
dressings,  or  hands.  If  the  wound  is  primarily  aseptic  it  may  be 
infected  at  a  later  stage  by  dressings  which  are  not  aseptic. 
Infection  of  surgical  closed  wounds  is  uncommon  after  the  sixth 
day,  because  granulation  tissue  does  not  absorb  as  a  nongranu- 
lating  surface  does. 

So  long  as  microorganisms  continue  to  live  and  multiply  in 
the  tissues  about  a  wound  they  produce  a  soluble  toxin,  which 
causes  necrosis  of  tissue.  Into  the  necrotic  tissue  comes  exuda- 
tion. Consequently  effective  repair  cannot  occur  until  the 
microorganisms  are  destroyed.  The  result  of  the  infection  of 
wounds  is  excessive  destruction  of  tissue  and  a  prolongation  of 
the  time  required  for  healing. 

Wounds  may  be  infected  by  various  microorganisms  which  pro- 
duce suppuration,  but  the  action  of  the  different  organisms  results 
ordinarily  in  one  of  two  sorts  of  changes  in  the  tissues,  i.e.,  the 
organisms  may  produce  (i)  a  localized  necrosis,  exudation,  and 
solution  of  tissue  about  the  point  of  infection,  or  (2)  the  infec- 
tion may  extend  along  the  lymphatic  spaces  and  vessels,  and 
produce  a  more  extensive  and  diffuse  exudation  with  necrosis,  but 
without  marked  solution  of  tissue.  Infection  by  the  staphylococ- 
cus aureus  produces  typical  changes  of  the  first  kind  ;  infection 
by  the  streptococcus  produces  typical  lesions  of  the  second. 

Infected  closed  zvoiiiids :  If  a  closed  wound  is  infected  the 
infection  may  be  superficial  or  deep. 

If  the  infection  is  by  organisms  of  the  type  of  the  staphylo- 
coccus aureus,  and  is  superficial,  it  commonly  arises  from  infected 
sutures.  In  this  case  microorganisms  are  introduced  along  the 
track  of  the  suture,  multiply,  produce  a  toxin,  and  cause  necrosis 
of  tissue  and  exudation  along  the  suture,  i.e.,  a  stitch  abscess 
occurs  (see  Sutures).  The  infection  frequently  remains  limited 
to  the  tissue  about  the  suture,  but  may  extend  to  and  infect  the 
entire  wound. 


9 


If  deep  infection  by  organisms  of  the  type  of  the  staphylo- 
coccus occur  the  closed  wound  becomes  practically  an  abscess 
cavity.  Microorganisms  multi[jly  in  the  exudate  and  in  the 
tissues  about  the  wound,  produce  a  soluble  toxin,  which  causes 
necrosis  and  solution  of  tissue.  Into  the  necrotic  and  dissolv- 
ing area  comes  exudate,  in  which  leucocytes  predominate,  i.e., 
pus.  If  proliferation  of  connective  tissue  and  vessels  has  begun, 
this  granulation  tissue  may  be  infected  and  destroyed.  About 
the  area  of  solution  new  granulation  tissue  continues  to  form. 
This  process  of  exudation,  solution,  and  formation  of  granulation 
tissue  continues  until  the  contents  of  the  infected  wound  are 
allowed  to  escape,  or  until  the  microorganisms  die. 

In  closed  wounds  the  products  of  such  an  infection  usually  are 
discharged  early  through  the  original  wound,  but  if  the  edges  of 
the  wound  have  united  early  the  amount  of  solution  of  tissue  may 
be  great.  In  this  case,  a  condition  is  left  exactly  similar  to  the 
condition  seen  after  an  abscess  has  been  opened,  and  the  further 
steps  of  the  healing  are  like  those  occurring  in  the  healing  of  an 
abscess  (see  Abscess).  The  process  may  extend  to  the  super- 
ficial layers  of  the  wound  and  cause  necrosis  and  solution  of  the 
approximated  edges  of  the  wound,  and  result  in  the  formation 
of  an  open  wound  (ulcer).  If  this  occur  the  further  steps  in  the 
healing  process  are  those  already  described  under  open  wounds 
{vide  supra),  i.e.,  granulation. 

The  gross  appearances  of  closed  wounds  thus  infected  are 
characteristic.  Pain,  heat,  redness,  and  swelling  about  the 
wound  are  marked.  The  edges  of  the  wound  are  swollen,  red- 
dened, and  gelatinous.  In  a  short  time  gaps  appear  in  the  line 
of  incision,  through  which  is  discharged  yellow  or  bloody  pus. 
The  edges  of  the  wound  may  become  entirely  necrotic,  separate, 
and  gape,  disclosing  a  cavity  lined  with  yellow  or  gray  sloughs 
of  necrotic  granulation  tissue.  If  these  sloughs  are  forcibly 
removed  they  expose  a  raw,  bleeding  surface  of  granulation 
tissue.  After  the  infection  ceases  an  open  wound  is  left  similar 
in  appearances  to  an  uninfected  open  wound.  Such  a  wound 
heals  by  granulation. 

If  a  closed  wound  become  infected  by  microorganisms  of  the 
type  of  the  streptococcus  the  organisms  multiply  and  produce 
lesions  like  those  seen  in  lymphangitis  (z'z^/i?  Diffuse  Suppuration). 
In  that  case  solution  of  tissue  is  less  marked  than  in  the  type  of 
infection   just    described,  although    some    solution    does    occur. 


10 


Necrosis  of  tissue,  however,  is  usually  extensive,  and  leads  to  the 
formation  of  extensive  sloughs,  which  must  be  disintegrated  or 
removed  before  healing  can  be  completed.  'I'he  removal  of 
this  necrotic  material  usually  results  in  the  formation  of  a  more 
or  less  extensive  open  wound,  which  heals  by  granulation,  as 
already  described. 

The  gross  appearances  of  such  an  infection  are  characteristic. 
The  wound  is  reddened,  painful,  swollen,  hot,  and  tender.  If  the 
extension  of  the  infection  is  along  the  lymphatic  vessels,  a  dis- 
tinct red  line  can  be  seen  extending  from  the  wound  alon^  the 
line  of  lymphatics.  Tissues  along  the  line  of  extension  are 
swollen  and  tender.  Groups  of  lymph  nodes  became  swollen, 
tender,  and  may  soften  and  form  abscesses.  If  the  condition  is 
not  relieved  general  infection,  septicaemia,  and  toxaemia  often 
occur. 

If  the  extension  is  along  connective  tissue  clefts  ("  cellulitis," 
"  phlegmon  ")  the  tissues  about  the  wound  may  show  very  exten- 
sive, diffuse  redness,  and  heat  and  swelling,  and  be  very  painful. 
In  this  case  extension  of  the  infective  process  through  the  walls 
of  adjacent  vessels  is  common,  and  results  in  the  formation  of 
thrombi,  with  sometimes  embolism  and  formation  of  metastases. 
Tissues  about  the  wound  usually  become  necrotic  and  form 
sloughs  which  must  be  removed  before  healing  can  take  place. 
Removal  of  these  sloughs  leaves  an  open  wound  which  heals  by 
granulation. 

Infected  open  ruoi/nds :  Infection  of  open  wounds  may  be  due 
to  organisms  of  the  type  of  the  staphylococcus  or  of  the 
streptococcus. 

Staphylococcus  type  :  Infection  by  such  organisms  leads  to  a 
multiplication  of  organisms  with  a  production  of  toxins,  fol- 
lowed by  necrosis,  solution  of  tissue,  and  suppuration.  The  sur- 
face of  the  wounds  breaks  down,  dissolves,  and  the  area  of  the 
wound  enlarges.  After  the  infection  ceases  an  open  wound  is 
left  to  heal  by  granulation. 

Gross  appearances  :  The  edges  of  the  wound  are  red,  swollen, 
hot,  and  tender.  The  surface  is  covered  with  a  profuse  purulent 
discharge,  beneath  which  is  gray,  necrotic  granulation  tissue. 
After  the  process  ceases  a  wound,  more  extensive  than  the 
original  one,  is  left  to  heal  by  granulation. 

Stre])tococcus  type  :  Infection  by  such  organisms  leads  to  mul- 
tiplication of  organisms  with  production  of  toxin  and   necrosis 


11 


with  solution  of  tissue.  As  in  closed  wounds,  the  extension  may 
extend  along  lymphatic  vessels,  or  connective  tissue  clefts.  In 
each  case  the  conditions  are  like  those  already  described  under 
corresponding  circumstances  in  closed  wounds. 

Gross  appearances  correspond  to  those  already  described 
under  closed  wounds. 

Ptinciples  of  hraiment  of  wounds :  From  a  consideration  of 
the  process  of  repair  of  wounds  certain  simple  fundamental  prin- 
ciples of  treatment  are  obvious. 

Surgical  cleanliness  is  the  most  important  factor,  and  is  practi- 
cally under  control.  This  cleanliness  applies  to  the  field  of 
operation,  to  the  hands  of  the  operator,  instruments,  sponges, 
sutures,  dressing,  and  to  all  materials  which  in  any  way  are  brought 
into  contact  with  the  wound.  If  perfect  surgical  cleanliness 
(asepsis)  is  obtained,  the  amount  of  tissue  to  be  repaired  is 
dependent  solely  upon  the  size  of  the  original  wound.  If  pyogenic 
infection  occurs,  the  destruction  of  tissue  depends  upon  the  extent 
of  infection,  and  in  all  cases  the  extent  of  the  wound  and  the 
length  of  time  required  to  replace  the  defect  are  increased,  to 
say  nothing  of  the  dangers  of  septicaemia,  etc. 

Avoidance  of  manipulation  is  also  extremely  desirable.  In 
wounds  in  which  long-continued  or  violent  manipulation  is  car- 
ried on,  the  destruction  of  tissue  extends  very  widely  beyond  the 
mere  limits  of  a  surgeon's  incision,  and  in  such  cases  the  amount 
of  tissue  to  be  replaced  is  much  greater  than  the  mere  incision 
would  require.  Even  in  incised  wounds  the  extent  of  the  repar- 
ative process  beyond  the  line  of  incision  is  much  greater  than 
usually  is  appreciated.  For  this  reason  it  is  desirable  for  the 
surgeon  to  make  free,  sweeping  incisions,  rather  than  a  series  of 
little  cuts. 

Perfect  and  complete  hjemostasis  also  is  necessary  to  obtain  ' 
rapid  healing  of  wounds.  The  greater  the  amount  of  haemorrhage 
between  the  edges  of  aseptic  wounds  the  greater  the  length  of 
time  required  for  healing.  The  haemorrhage  separates  the  edges 
of  the  wound  and  increases  the  area  to  be  organized  by  granula- 
tion tissue.  Excessive  amount  of  blood  in  a  closed  wound  also 
furnishes  an  excellent  culture  medium  for  the  growth  of  pyogenic 
organisms,  if  any  are  present. 

Accurate  closure  and  approximation  of  the  edges  of  wounds 
in  which  an  attempt  is  made  to  obtain  primary  union  are  essential. 
The  approximation  should  affect,  not  only  the  superficial  edges, 


1-J 


but  especially  the  deeper  layers  of  the  wound.  Even  with  care- 
ful operators  it  is  astonishing  to  see,  on  examining  sections  with 
a  microscope,  how  very  imperfect  the  closure  of  the  wound  is. 
The  more  accurately  the  epidermis  is  approximated  the  less  the 
surface  to  be' covered  by  proliferating  epithelium.  The  quicker 
the  wound  is  covered  by  epithelium  the  less  the  liability  of  infec- 
tion. The  more  carefully  the  deeper  layers  are  approximated  and 
dead  spaces  are  obliterated  the  less  the  amount  of  inflammatory 
exudate  and  blood  to  be  removed  and  organized  by  granulation 
tissue,  and  the  smaller  the  scar. 

Aseptic  protection  of  the  wound  is  essential  during  the  early 
days  of  the  reparative  process.  The  danger  of  secondary  infec- 
tion is  over  when  the  wound  is  covered  by  epithelium,  and  the 
exudate  is  entirely  replaced  by  granulation  tissue.  The  power  of 
resistance  to  infection  by  a  wound  covered  with  granulation  tissue 
is  much  greater  than  in  the  earlier  stages  before  the  formation  of 
granulation  tissue. 

Fixation  of  wounded  tissue  also  is  essential  to  avoid  continua- 
tion of  injury  to  fresh  or  granulating  edges  of  the  wound.  This 
fixation  may  be  obtained  in  a  variety  of  ways. 

In  regard  to  open  wounds  there  are  certain  special  precautions. 
Surgical  asepsis  is  as  desirable  as  in  closed  wounds,  but  perfect 
asepsis  is  not  feasible  in  wounds  which  remain  open  for  long 
intervals.  The  reason  that  extensive  open  wounds  do  not  oftener 
become  seriously  infected  is  that  healthy  granulation  tissue  has  a 
marked  power  of  resistance  to  absorption  of  pyogenic  organisms. 
On  the  surface  of  open  wounds,  in  the  early  stages,  masses  of 
necrotic  tissue  ("sloughs")  often  are  present.  It  is  better  not 
to  attempt  too  vigorous  removal  of  these,  as  their  forcible  removal 
leads  to  repeated  traumatism  of  the  young  granulation  tissue 
beneath  them,  with  a  consequent  prolongation  of  the  time  of 
healing  and  increased  danger  of  pyogenic  infection. 

In  open  wounds  also  it  is  desirable  to  keep  the  granulation 
tissue  below  the  level  of  the  advancing  epithelial  edge,  as  epithe- 
lium often  is  unable  to  cover  over  exuberant  granulations. 

In  many  cases  of  extensive  open  wounds  the  epithelium  ceases 
to  advance  over  the  granulating  area,  and  in  such  cases  it  becomes 
necessary  to  cover  in  the  epithelial  defect  by  small  isolated  grafts, 
plastic  flaps,  or  Thiersch  grafts. 

Regulation  of  the  blood  supply  always  is  desirable  in  open 
wounds.     Venous  stasis  always  appears  to  interfere  both  with  the 


13 


formation  of  granulation  tissue  and  with  the  advance  of  the 
epithelium.  Prevention  of  venous  stasis  can  be  obtained  by 
pressure,  by  removal  of  varicose  veins,  or  by  position. 

II.  Sutures  :  Various  substances  are  used  as  sutures  to 
approximate,  support,  and  hold  in  position  the  edges  of  wounds. 
These  artificial  supports  must  be  retained  in  position  until  the 
process  of  repair  is  so  advanced  that  they  no  longer  are  needed. 
If  the  wound  is  superficial  the  ends  of  the  suture  remain  visible 
and  may  be  removed  after  repair  is  completed.  Sometimes  a 
superficial  wound  is  closed  by  a  suture  which  is  buried  in  the 
edges  of  the  skin,  and  such  sutures  usually  are  not  removed.  If 
the  wound  is  a  deep  one  deep  sutures  may  be  buried  in  the 
tissue  and  cannot  be  removed  after  healing  is  completed. 

Sutures  may  be  soluble  in  the  tissues,  or  insoluble.  Soluble 
sutures  include  catgut,  plain  or  chromicized,  and  various  animal 
tendons.  Insoluble  sutures  include  silk,  silk-worm  gut,  silver 
wire,  horse-hair,  and  celloidin. 

The  reaction  produced  in  the  tissues  depends  partly  upon 
whether  the  suture  is  soluble  or  insoluble.  The  primary  result 
of  the  introduction  of  sutures  is  the  production  of  a  minute 
wound.  Soluble  sutures  at  first  act  as  a  foreign  body,  but  after  a 
time  are  dissolved,  absorbed,  and  leave  a  gap  in  the  tissue,  which 
is  filled  by  scar  tissue.  Insoluble  sutures  act  as  a  foreign  body 
indefinitely,  unless  removed,  and  finally  are  surrounded  and 
encapsulated  by  scar  tissue. 

Catgut  may  be  taken  as  the  type  of  soluble  suture  ;  silk  as  the 
type  of  insoluble. 

Catgut  sutures :  Introduction  of  the  suture  causes  a  minute 
wound.  Along  the  track  of  the  suture  and  extending  some 
little  distance  into  the  surrounding  tissues  comes  an  exudation. 
The  gut  soon  becomes  swollen  and  fibrillated.  Leucocytes 
appear  between  the  fibrillse  and  at  the  periphery  of  the  suture. 
Wherever  they  appear  there  is  marked  solution  of  the  suture,  so 
that  it  becomes  much  reduced  in  size.  About  the  inflammatory 
area  a  layer  of  granulation  tissue  is  formed,  well  marked  on  the 
third  day.  In  this  granulation  tissue  giant  cells  are  few  or  want- 
ing. In  about  ten  to  fourteen  days  the  gut  is  entirely  absorbed, 
the  exudation  disappears,  and  the  space  occupied  by  the  suture 
is  filled  by  granulation  tissue.  At  length  this  granulation  tissue 
becomes  dense  scar  tissue. 


14 


Gross  appearances  :  At  first  the  tissue  about  the  suture  shows 
slight  swelling  and  redness.  After  a  few  days,  if  the  suture  is 
removed,  it  leaves  a  small  circular  hole  from  which  serum  and  a 
few  leucocytes  can  be  expressed.  At  the  end  of  about  ten  days 
the  external  portion  easily  separates  at  the  level  of  the  skin,  due 
to  the  fact  that  the  buried  portion  of  the  suture  is  dissolved,  and 
a  tiny  red  circular  scar  of  granulation  tissue  shows  the  former  site 
of  the  suture.  In  time  this  becomes  a  minute  white  scar,  or 
sometimes  may  disappear. 

Si/k  sutures  :  As  in  the  case  of  catgut  the  introduction  of  the 
suture  causes  a  minute  wound,  which  in  a  few  hours  is  filled  with 
exudate.  The  exudate  extends  for  some  distance  into  surround- 
ing tissues.  The  leucocytes  appear  in  large  numbers  between  the 
fibres  of  the  silk.  In  about  forty-eight  hours  proliferation  and 
formation  of  granulation  tissue  about  the  suture  is  marked.  This 
granulation  tissue  replaces  the  exudate  and  may  even  extend  be- 
tween the  fibres  of  the  silk.  In  this  young  connective  tissue 
appear  many  giant  cells,  which  generally  lie  in  close  approxima- 
tion to  individual  fibres.  Ultimately  the  exudate  disappears, 
leaving  the  suture  encapsulated  and  enmeshed  in  dense  fibrous 
tissue.     Giant  cells  may  persist  for  months  or  years. 

Gross  appearances  :  Superficial  silk  sutures  generally  are  re- 
moved at  about  the  tenth  day.  When  removed  they  leave  a  small 
circular  wound  from  which  serum  and  a  few  leucocytes  caabe 
expressed.  This  wound  is  closed  by  granulation  tissue  in  a  few 
hours.     At  length,  only  a  minute  white  scar  is  left. 

Sutures  of  chromicized  catgut,  or  kangaroo,  or  other  tendons, 
are  much  less  soluble  than  catgut,  but  generally  are  ultimately 
absorbed.  At  times,  however,  they  may  persist  for  years.  In 
such  a  case  it  is  probable  they  are  encapsulated.  Silk-worm  gut, 
silver  wire,  and  horse-hair  are  insoluble  and  not  fibrillated,  so  that 
no  infiltration  or  enmeshing  of  the  suture  can  occur. 

Either  silk  or  catgut  sutures  may  be  septic.  In  that  case  the 
track  of  the  suture  may  become  infected  with  microorganisms, 
and  become  a  minute  abscess  cavity.  The  infection  may  remain 
confined  to  the  track  of  the  suture,  or  may  extend  and  infect  the 
entire  wound  (see  Infected  Incised  Wounds). 

No  ideal  or  perfect  suture  has  as  yet  been  discovered.  A 
suture  which  is  perfectly  satisfactory  for  one  purpose  may  be  very 
unsatisfactory  for  another. 


15 


III.  Wounds  of  thk  intestines:  When  any  portion  of  the  in- 
testinal tract  is  wounded,  it  is  essential  that  the  wound  be  closed 
at  once  in  such  a  way  as  to  render  the  wall  of  the  intestine  water- 
tight as  soon  as  possible,  so  as  to  avoid  leakage  of  the  infectious 
contents.  Consequently  many  methods  have  been  devised  to 
give  as  perfect  as  possible  mechanical  closure,  which,  however,  is 
never  absolutely  jjcrfect ;  and  the  serous  surfaces  of  the  cut  edges 
always  are  approximated,  because,  if  mucous  membrane  surfaces 
are  brought  together,  repair  does  not  begin  until  the  epithelium 
has  been  sloughed  off;  while,  when  the  external  (serous)  surfaces 
are  approximated,  the  production  of  fibrinous  exudate  is  very 
rapid,  and  in  a  very  few  hours  makes  the  wound  water-tight,  pro- 
vided too  much  mechanical  tension  is  not  put  on  the  wound. 
Many  methods  of  suture  have  been  devised  to  close  the  intestine. 
In  some  cases  the  suture  may  penetrate  all  the  coats  of  the  gut, 
but  these  sutures  as  a  rule  are  applied  merely  to  give  fixation  oi 
the  wounded  edges.  The  sutures  which  approximate  the  serous 
surfaces  of  the  intestine  should  not  extend  fronn  the  lumen  of  the 
intestine  to  the  peritoneal  cavity,  for  if  they  do  they  make  a 
wound  connected  with  the  infected  intestinal  canal,  and  infection 
along  the  suture  may  lead  to  infection  of  the  general  peritoneal 
cavity.  The  best  suture  is  one  which  gives  the  strongest  and 
most  perfect  immediate  mechanical  closure  of  the  wound  without 
allowing  any  connection  of  infected  intestine  with  peritoneal 
cavity,  and  also  gives  the  most  perfect  approximation  of  the 
external  serous  coat  without  diminution  of  the  calibre  of  the  in- 
testine. It  may  be  said  that  without  doubt  the  best  suture 
material  on  the  whole  is  silk  or  celloidin,  as  animal  sutures  soften 
so  early  that  they  do  not  maintain  perfect  approximation  until 
the  wound  is  completely  organized.  Mechanical  devices  should 
be  used  only  for  special  clinical  reasons.  The  process  of  repair 
is  the  same  no  matter  what  mechanical  method  is  used,  but  the 
process  described  is  such  as  is  seen  after  suture. 

The  reaction  produced  by  the  suture  corresponds  to  that 
already  described,  and  will  be  ignored  in  describing  the  process 
of  repair.  Serous  surfaces  are  approximated  because  of  the  large 
amount  of  exudate  formed  from  serous  surfaces,  which  quickly 
seals  the  wound  hermetically. 

The  wounded  area  is  filled  quickly  with  exudate  and  all  layers 
of  the  gut  are  infiltrated.  The  invaginated  edges  necros  -  and 
the  endothelium  between  the  approximated  edges,  and  for  a  con- 


u; 


sulerable    distance    on    either   side    of   the    wound,    dis.ii)i)ears. 
lOxutlate  extends  over   tlie  serous  surface   for  a  consi<ierable   dis- 
tance beyond  the  limits  of  tlie  wound  (aseptic  local   peritonitis). 
Korni.Uion  of  fibrin  (juickly  seals  the  inverted  serous  surfaces  and 
prevents  leakage  of  intestinal  contents.      In  a  very  few  hours  (24) 
there  appears   extensive  proliferation   of  connective   tissue,  espe- 
cially of  the  subserous  connective  tissue,  and  a  formation  of  new 
vessels.     This  granulation  tissue  extends  into  the  exudate  from 
either  side,  the  exudate  disappears,  and  by  fusion  of  the  layers  of 
granulation  tissue  the  external   surfaces  of  the  gut  are  joined  by 
granulation   tissue.     'I'his   process  may  be  completed  as  early  as 
the  seventh  day,  although   union  generally  is  not  fiim  before  the 
tenth  day.     .Meanwhile   the  inverted   edges  become  necrotic  and 
dissolve,  leaving  an  ulcer  on  the  mucous  surface  of  the  gut.     The 
outer  surface  of  the  gut,  for  a  distance  of  several  inches,  may  be 
covered   by  exudate,  which   finally  is  converted    into  granulation 
tissue.     At  length  the  granulation   tissue  between   the  inverted 
edges  may  become  dense   fibrous   tissue  (intestinal  scar).     The 
internal  ulcer  heals,  and   there  may  be  a  partial   reproduction  of 
intestinal    glands.      The    external    exudate    becomes    organized. 
This  organization  of  the  external  exudate  may  cause  adhesions  to 
other  serous  surflices.     As  the  granulation  tissue  is  converted  into 
dense   fibrous  tissue,   some   contraction  may  occur,  and,  unless 
l)rovided  for,  may  lead   to  reduction  of  the  calibre  of  the  lumen 
of  the  gut. 

Gross  appearances  :  For  the  first  day  or  so  the  inverted  edges 
form  a  marked  projection  into  the  lumen  of  the  gut.  Between 
the  serous  surfaces  is  a  layer  of  adhesive  exudate.  The  outer 
surfiice  of  the  gut  is  injected  and  covered  with  a  layer  of  fibrin- 
ous exudate.  In  a  few  days  more  the  invaginated  edges  begin  to 
melt  down  and  disappear,  and  a  more  or  less  raised  ulcer  appears 
on  the  inner  surface  of  the  gut. 

The  wound  is  closed  by  a  red  line  of  organizing  exudate, 
while  the  external  exudate  becomes  firmer,  and,  possibly,  firmly 
adherent  to  adjacent  viscera  from  the  presence  of  granulation 
tissue.  In  the  course  of  a  few  weeks  the  internal  surface  is 
covered  by  more  or  less  complete  mucous  membrane,  the  wound 
is  closed  by  a  barely  visible  white  scar,  while  the  external  surface 
of  the  gut  is  opaque  and  dull  from  the  presence  of  fibrous  tissue. 
Ultimately  it  may  be  impossible  to  find  the  point  of  incision. 

The  process  of  repair  in  wounds  of  the   intestine  usually   is 


more  rapid  than  in  wountls  of  tlie  surface  of  the  body.  The 
wound  is  sealed  by  fibrinous  exudate  within  a  very  few  hours, 
although,  of  course,  the_  fibrin  can  easily  be  displaced  under  great 
tension.  In  many  cases  the  organization  of  the  exudate  is  com- 
pleted in  seven  days,  although  it  is  to  be  remembered  that  granu- 
lation tissue  at  this  time  still  is  very  fragile.  Rapidity  of  union  is 
favored  by  accurate  approximation  of  serous  surfaces  and  by 
avoiding  manipulation  as  far  as  possible,  so  as  to  avoid  traumat- 
ism of  the  approximated  edges. 

IV.  Repair  of  tendons  :  Tendons,  aponeuroses,  and  liga- 
ments are  special  types  of  connective  tissue.  What  has  already 
been  said  about  the  repair  of  connective  tissues  in  wounds  ap- 
plies in  a  general  way  to  the  repair  of  tendons,  but  tendons  are 
connective  tissue  with  a  special  function  and  a  special  structure, 
and  the  details  of  the  process  of  repair  vary  somewhat  from  the 
process  as  seen  in,  e.g.,  subcutaneous  connective  tissue,  and  de- 
serve especial  mention.  To  understand  the  process  of  repair  it 
is  necessary  to  bear  in  mind  the  anatomy  of  a  normal  tendon. 

Tendons  are  composed  of  the  densest  sort  of  fibrous  tissue 
arrayed  in  parallel  bundles,  closely  connected,  with  relatively  few 
elastic  tissue  fibres.  Surrounding  the  tendons  is  a  layer  of  loose 
areolar  tissue  (the  peritendineum)  from  which  septa  run  into 
the  tendon,  dividing  it  into  large  (secondary)  and  smaller  (pri- 
mary) bundles  of  dense  fibres.  These  dense  fibres  appear, 
under  the  microscope,  wavy  from  contraction,  and  anastomose 
more  or  less  with  each  other.  Between  the  fibres  are  cells  which 
on  long  section  are  oval  or  rectangular,  but  on  cross  section  are 
stellate,  and  are  united  to  other  similar  cells  by  processes,  thus 
separating  the  fibres  into  bundles. 

When  a  tendon  is  divided  there  always  is  considerable  retrac- 
tion of  the  divided  ends.  This  is  due  partly  to  contraction  of 
the  muscle  of  the  tendon  and  partly  to  contraction  of  the  fibres 
of  the  tendon  itself.  The  peritendineum  seldom  retracts  to  the 
same  extent  as  the  tendon  but  becomes  markedly  fibrillar  and 
folds  over  the  retracted  end  of  the  tendon.  Into  the  interval 
between  the  retracted  tendon  ends  comes  an  inflammatory  exu- 
date, with  perhaps  some  haemorrhage.  The  mesh  of  the  peri- 
tendineum is  filled  with  exudate,  but  the  exudate  extends  only  a 
little  way  into  the  cut  ends  of  the  tendon  itself.  Very  early  there 
begins  a  very  rapid  proliferation  of  connective  tissue  cells  from 


18 


the  connective  tissue  of  the  mesh  of  the  peritendineimi,  not  only 
between  the  retracted  ends  of  the  tendon,  but  also  from  the  peri- 
tendineum outside  the  tendon  ends,  thus  forming  a  spindle- 
shaped  swelling  much  like  the  callus  of  a  fracture.  At  the  same 
time  new  blood  vessels  are  formed.  In  this  spindle  of  granula- 
tion tissue  intercellular  fibrils  appear  very  early  to  an  extent 
much  more  marked  than  in  ordinary  connective  tissue.  The 
cells  of  the  tendon  take  very  little  part  in  this  process  of  pro- 
liferation, and  the  original  dense  fibres  of  the  tendon  not  at  all. 
There  is,  however,  marked  proliferation  of  the  connective  tissue 
cells  of  the  connective  tissue  septa  of  the  tendon,  which  extend 
between  the  dense  fibres  of  tendon  proper.  As  the  proliferation 
continues  the  exudate  disappears,  and  finally  the  cut  ends  are 
joined  by  a  spindle  of  granulation  tissue.  The  blood  vessels 
disappear  very  early,  granulation  tissue  fibrils  are  formed  in  large 
:imounts,  and  a  spindle  of  dense,  fibrous  tissue  joins  the  cut  ends. 
In  time  the  new  intercellular  fibrils  cannot  be  distinguished  from 
the  original  tendon  fibres,  the  new  tissue  becomes  of  the  same 
size  as  the  original  tendon,  and  cannot  be  distinguished  by  the 
naked  eye  from  the  uninjured  tendon. 

The  time  required  for  the  process  is  variable,  depending  upon 
the  size  of  tendon  and  upon  the  amount  of  separation.  The 
formation  of  completely  organized,  dense,  fibrous  tissue  in  smaller 
tendons  is  completed  in  about  two  weeks.  In  larger  tendons  the 
process  is  somewhat  longer.  The  tendon  practically  always  is 
sufficiently  regenerated  to  allow  passive  motion  in  about  three 
weeks. 

In  some  cases  tendons  fail  to  unite  or  may  unite  imperfectly. 
If  the  cut  tendon  ends  are  too  widely  separated,  the  connective 
tissue  of  adjacent  connective  tissue  may  interpose,  and  the  gap 
be  filled  with  ordinary  scar  tissue  instead  of  with  connective  tissue 
arising  from  the  peritendineum ;  or  again,  even  if  the  two  tendi- 
nous ends  become  united  with  new  tendon  derived  from  the 
peritendineum,  the  new  tissue  may  become  adherent  to  the  new 
connective  tissue  of  the  adjacent  skin,  etc.,  so  that  imperfect 
function  results.  Also,  where  several  tendons  are  divided  in  one 
wound,  f.g.,  in  accidental  wounds  about  the  wrist,  especially  if  the 
tendons  are  divided  in  some  place  where  the  tendon  sheaths  are 
not  sharply  defined,  the  newly-formed  tissue  between  the  ends  of 
adjacent  tendons  may  unite  into  one  common  mass,  thus  leading 
to  very  imperfect  function.     In   the  same  way,  even  when  only 


19 


one  tendon  is  divided,  it  may  adhere  to  the  connective  tissue  wall 
of  its  sheath.  In  the  case  of  tendons  lying  in  sharply  defined 
sheaths,  a  large  amount  of  separation  is  possible.  In  cases  where 
several  tendons  lie  close  together,  less  separation  is  possible.  In 
such  cases  it  often  is  better  to  fill  the  gap  by  some  one  of  the 
many  methods  of  splicing  the  tendon,  in  order  to  be  sure  that  the 
line  of  the  tendon  is  maintained  by  peritendineum  from  which 
the  new  tendon  is  to  be  formed. 

V.  Fracturks  :  If  a  bone  is  fractured,  usually  the  ends  of  the 
bone  are  more  or  less  displaced,  fragments  of  bone  may  lie  loose 
in  the  tissues,  there  usually  is  more  or  less  stripping  of  the  peri- 
osteum, with  crushing  of  adjacent  soft  parts,  and  some  hgemor- 
rhage.  After  a  few  days  a  fusiform  mass  (the  "callus")  is 
formed  about  the  fractured  ends,  and  persists  for  a  time.  After 
the  ends  of  the  bone  are  firmly  united  the  callus  disappears  more 
or  less  completely,  and,  if  the  ends  of  the  bone  are  accurately 
approximated,  the  external  appearance  of  the  bone  becomes 
normal. 

The  process  of  repair  of  fractured  bone  is  best  studied  in  bones 
in  which  a  loss  of  tissue  has  been  produced  without  dislocation 
of  fragments,  e.g.,  by  drilling  a  small  hole  vertically  into  the  shaft 
of  a  bone.  In  this  way  the  reparative  process  is  uncomplicated. 
Later,  the  more  complex  process  seen  in  ordinary  fractures  easily 
is  understood.  The  process  as  seen  in  experimental  drill-holes 
is  described  first,  then  the  more  complicated  process  of  coniplete 
fracture. 

Experimental  ft  acture  (drill-hole)  :  As  a  result  of  the  injury, 
haemorrhage  occurs,  followed  in  a  few  hours  by  more  or  less 
exudate  of  leucocytes,  serum,  and  fibrin. 

By  the  second  day  proliferation  of  connective  tissue  and  of  the 
endothelium  of  blood  vessels  begins.  This  proliferation  of  con- 
nective tissue  occurs  external  and  internal  to  the  cortex  of  the 
bone.  The  external  proliferation  arises  from  the  periosteum,  and 
results  in  the  formation  of  a  spindle-shaped  mass  of  connective 
tissue,  in  which  are  young  blood  vessels  derived  from  neighboring 
blood  vessels,  about  the  injured  point  (early  "external  callus"). 
The  internal  proliferation  arises  from  the  connective  tissue  of  the 
marrow,  which  lies  next  to  the  cortex  of  the  bone  (endosteum), 
and  so  appears  as  a  mass  of  young  connective  tissue  about  the 
edges    of  the    drill-hole    ("  myelogenous    callus ")    and,    if  the 


20 


injury  has  been  sufficiently  deep,  from  the  endosteum  of  the  bone 
opposite  the  drill-hole.  At  this  period  remnants  of  exudate 
l)ersist.  l-'ragnients  of  necrotic  cortical  bone  carried  in  by  the 
drill  may  be  seen 

By  the  fourth  day  a  homogeneous  intercellular  substance 
("osteoid  tissue")  appears  between  many  of  the  granulation 
tissue  cells  of  the  internal  callus.  In  this  osteoid  tissue,  at  a 
later  period,  lime  salts  are  deposited ;  i.e.,  it  represents  the 
earliest  outline  of  new  bone  trabecule.  In  this  homogeneous 
material  are  included  some  of  the  connective  tissue  cells  which 
later  are  to  become  "  bone  corpuscles."  Certain  connective 
tissue  cells  at  the  periphery  of  these  new  trabeculae  deposit  suc- 
cessive layers  of  osteoid  tissue,  i.e.,  act  as  "osteoblasts." 

Formation  of  osteoid  tissue  also  takes  place  in  the  external 
layer  of  granulation  tissue  of  the  external  callus. 

By  the  end  of  a  week,  the  exudate  has  nearly  disappeared. 
Trabeculje  are  well  developed  both  in  external  and  internal  con- 
nective tissue.  The  spaces  between  the  trabecule  are  filled 
with  young  connective  tissue  cells  and  young  blood  vessels.  Many 
osteoblasts  lie  about  the  trabecule  and  osteoclasts  appear.  The 
external  callus  covers  in  the  wound  produced  by  the  drill.  The 
internal  callus  may  partly  or  completely  fill  the  medullary  canal 
at  the  point  of  injury.  The  cortical  ends  of  the  bone  take  no 
])art  in  the  i^roliferative  process,  but  the  hole  in  the  cortex 
becomes  filled  with  granulation  tissues  which  extend  from  the 
external  callus  inwards,  and  from  the  internal  callus  outwards. 

At  the  end  of  about  four  weeks  both  external  and  internal 
callus  are  composed  entirely  of  newly-formed  trabecule,  and  the 
mass  of  fibrous  tissue  which  filled  the  drill-hole  is  converted  into 
young  bone  and  unites  the  separated  cortical  ends.  The  young 
trabecule,  as  a  rule,  lie  at  right  angles  to  the  original  shaft. 
Many  osteoblasts  are  seen  lying  close  to  the  trabeculae. 

Ultimately  the  external  callus  is  absorbed  and  largely  dis- 
appears. The  internal  callus  also  may  be  absorbed,  and  the 
marrow  canal  restored.  The  trabeculae  between  the  separated 
cortical  ends  remain,  become  closely  attached  to  the  separated 
cortical  ends  and  restore  the  line  of  the  cortex,  and  repair  is 
completed.  In  time  the  trabeculae  rearrange  themselves,  so  as  to 
lie  parallel  with  the  line  of  cortical  bone. 

Observe  that    in  experimental  drill-holes  the  transition    from 


21 


granulation  tissue   to  bone   is    direct,   without    the    fnrination   of 
cartilage  as  an  intermediate  stcj). 

Complete  fraciures  :  The  general  process  is  the  same,  but  there 
are  slight  modifications  in  detail.  In  complete  fractures  the  ends 
of  the  bones  are  more  or  less  dislocated,  since  exact  approxima- 
tion of  the  ends  of  the  bones  seldom  occurs.  Injury  to  soft 
tissues  also  is  more  extensive. 

When  proliferation  begins,  it  arises  internally  from  the  connec- 
tive tissue  of  the  marrow  ("  medullary  callus"),  externally  both 
from  the  periosteum  and  from  the  connective  tissue  of  adjacent 
soft  parts  ("external  callus").  Consequently  the  external  callus 
appears  relatively  much  larger  than  in  drill-hole  fractures,  and 
forms  a  large  fusiform  mass  which  includes  the  dislocated  ends 
of  both  fragments.  This  external  callus  at  first  is  composed 
entirely  of  granulation  tissue,  and  no  distinction  can  be  made 
between  the  portion  which  has  arisen  from  the  periosteum  and 
that  which  has  arisen  from  the  soft  tissues. 

When  trabeculse  appear  they  may  form  directly  from  granula- 
tion tissue,  as  occurs  in  drill-hole  fractures,  but  commonly  in 
complete  fractures  the  granulation  tissue  nearest  the  shaft  of  the 
bone  becomes  dense  fibrous  tissue,  and  then  is  transformed 
(metaplasia)  into  cartilage.  As  this  metaplasia  of  connective 
tissue  extends  farther  into  the  fibrous  tissue  the  deeper  layers  of 
cartilage  are  converted  into  bone,  and  trabeculae  and  marrow 
spaces  appear.  The  process  of  repair  in  the  internal  callus 
resembles  that  described  under  drill-hole  fracture. 

Ultimately,  there  comes  more  or  less  absorption  of  the  tra- 
beculse of  the  callus,  and  a  restoration  of  the  shaft  to  approxi- 
mately its  original  condition.  If  the  dislocation  of  the  ends  is 
excessive,  much  of  the  callus  always  persists  ;  /.e.,  excessive  callus 
indicates  malposition  of  fractured  ends.  The  time  required  to 
repair  any  given  bone  depends  upon  the  size  of  the  bone,  the 
accuracy  with  which  the  ends  of  the  bone  are  approximated,  and 
the  care  with  which  they  are  immobilized. 

In  some  cases  bony  union  may  be  delayed  for  many  months  or 
may  never  occur.  The  cause  of  this  condition  is  not  clear. 
Sometimes  it  appears  to  be  due  to  mechanical  causes  (by  inclu- 
sion of  soft  tissue  between  fractured  ends),  at  other  times  it  is 
attributed  to  "  constitutional  "  causes.  In  some  cases  the  forma- 
tion of  osteoid  tissue  seems  complete,  but  for  some  unknown 
reason  no  deposition  of  lime  salts  occurs. 


22 


In  some  cases  the  ends  of  the  bone  are  united  by  dense  fibrous 
tissue  only,  so  that  a  flail-like  condition  persists  ("  syndesmosis  "). 
Or  one  fractured  end  may  enlarge  and  form  a  false  socket,  while 
the  other  end  forms  a  false  head  and  a  false  joint  ("pseudo- 
arthrosis") is  formed.  In  such  cases  the  two  ends  usually  are 
surrounded  by  a  capsule  of  dense  cicatricial  tissue.  The  articu- 
lating ends  of  the  bones  generally  are  covered  with  dense  fibrous 
tissue,  not  with  cartilage.  If  two  adjacent  bones  are  broken,  <f.(,^, 
both  bones  of  the  forearm,  there  may  be  fusion  of  the  calluses, 
and  the  two  bones  finally  be  firmly  united  ("synostosis"). 

Gross  appearances  :  After  a  fracture  the  soft  tissues  about  the 
fracture  soon  become  swollen  and  tense  from  the  pressure  of  exu- 
date. In  a  few  hours  blebs  and  bullae,  containing  a  clear  serous 
or  h?emorrhagic  fluid,  may  appear,  due  to  elevation  of  the  super- 
ficial layers  of  the  skin  by  the  fluid  exudate.  If  the  injury  to  soft 
tissues  is  severe  they  may  be  colored  bluish  at  once  by  extensive 
subcutaneous  haemorrhage,  or  the  tissues  may  appear  black  and 
blue  only  after  several  days,  due  to  deep  haemorrhage  and  disin- 
tegration and  diffusion  of  blood  pigment. 

After  the  exudate  diminishes  the  tissues  about  the  site  of  the 
fracture  are  thickened  and  form  a  spindle-shaped  mass  (granula- 
tion-tissue external  callus),  at  first  firm  and  elastic,  but  not  bony. 
After  about  two  weeks  the  callus  obviously  becomes  harder  and 
more  sharply  defined  (ossification  of  callus),  and  the  fragments 
which  at  first  were  freely  movable  are  much  less  so,  or  move  only 
under  strong  pressure.  After  a  variable  number  of  weeks,  de- 
pending upon  the  site  and  severity  of  the  fracture,  mobility 
entirely  disappears,  although  the  thickening  due  to  the  callus 
persists.  At  this  time  the  bone  is  strong  enough  to  bear  weight. 
In  the  course  of  months  the  callus  progressively  becomes  less 
(absorption  of  external  callus),  and  finally  becomes  very  small. 
Complete  absorption  seldom  occurs,  but  the  amount  of  callus 
which  persists  is  proportional  to  the  amount  of  deformity.  Per- 
sistence of  a  large  callus  almost  always  indicates  malposition  of 
the  broken  ends. 

Complkations :  Certain  complications  of  fractures  occur. 
Blood  vessels,  nerves,  or  tendons  may  be  torn  by  the  fractured 
ends  of  the  bone  at  the  time  the  injury  occurs.  If  large  blood 
vessels  are  injured  severe  haemorrhage  into  tissues,  or  even 
gangrene  of  an  extremity,  may  result.  If  nerves  are  injured 
jjaralysis    or    trophic    changes    may   occur.      Tendons    may    be 


28 


severely  injured,  and  become  adherent  to  tendon  sheaths  as 
repair  takes  place,  so  that  serious  disability  is  produced. 

If  the  cutaneous  tissues  are  wounded  at  the  time  the  break 
occurs,  an  open  wound  may  be  produced  leading  to  the  point  of 
fracture  (compound  fracture).  If  infection  of  the  wound  by 
pyogenic  organisms  take  place,  serious  or  fatal  suppuration  of 
the  bone  may  take  place   (traumatic  osteomyelitis,  <j.v.). 

Principles  of  treatment  of  fractures  :  Depend  upon  the  above- 
described  conditions. 

The  first  essential  is  as  perfect  as  possible  approximation  of 
the  fractured  ends.  The  more  perfect  the  position  of  the  fracture 
the  smaller  the  external  callus  and  the  shorter  the  time  required 
for  completion  of  repair  of  the  bone.  The  more  perfect  the 
position,  the  less  is  the  interference  with  the  soft  tissues,  and  in 
all  fractures  it  is  to  be  remembered  that  there  is  injury  not  only 
of  bone,  but  of  soft  tissues.  As  regards  the  reduction  of  the 
deformity  it  should  be  borne  in  mind  that  attempts  at  reduction 
more  than  two  weeks  after  injury  are  likely  to  give  poor  results. 
During  the  earlier  stages  the  callus  is  soft  and  not  ossified. 
After  the  second  week  bone  formation  is  well  advanced,  the  ends 
of  the  bone  are  included  in  the  spindle-shaped  callus,  are  not 
freely  movable  as  at  first,  and  forcible  correction  causes  injury 
to  the  newly-formed  bone  and  prolongation  of  the  process  of 
repair. 

Perfect  immobilization  also  is  essential.  The  less  the  callus  is 
interfered  with,  the  greater  is  the  rapidity  of  repair.  In  case  of 
fracture  about  tendons  or  into  the  articular  surfaces  of  joints, 
other  mechanical  problems  enter  in,  so  that  early  mobility  may 
be  necessary  and  the  importance  of  rapid  ossification  may  be 
•  secondary. 

VI.  Repair  of  muscle:  After  a  wound  of  striated  muscle 
there  comes,  as  in  all  injuries  of  the  soft  tissue,  an  inflammatory 
exudate.  In  the  course  of  a  few  hours  there  arises  a  new  growth 
of  granulation  tissue  from  the  adjacent  connective  tissue  and  also 
a  peculiar  series  of  changes  in  the  muscle  itself.  Some  of  the 
muscle  fibres  next  to  the  wound  become  necrotic  ;  they  are  in- 
vaded by  polynuclear  leucocytes  and  endothelial  cells,  dissolved, 
and  removed.  In  some  of  the  other  muscle  fibres  there  occurs 
an  increase  in  the  number  of  the  nuclei,  which  arise  not  by 
mitosis,  but   by  direct  nuclear  division.     These    nuclei  arrange 


24 


themselves  in  the  ends  of  the  muscle  fibres,  and,  instead  of 
having  a  mural  arrangement  like  that  of  the  nuclei  in  normal 
muscle  fibres,  are  situated  in  the  middle  of  the  fibre.  The  fibre 
itself  loses  its  strine,  and  becomes  more  or  less  fibrillaled  longi- 
ludinallv.  The  greater  jiortion  of  these  cells  finally  disappear, 
so  that  in  the  granulation  tissue  scar  only  an  occasional  club- 
ondetl  fibre  is  left,  and  the  defect  in  the  muscle  is  replaced  by 
granulation  tissue,  which  ultimately  becomes  scar  tissue.  If  the 
ends  of  the  muscle  are  accurately  approximated  the  scar  is  a 
small  one  and  interference  with  muscle  function  is  slight.  If  the 
ends  of  the  muscle  are  widely  separated,  there  may  be  great 
impairment  of  function. 

Vn.  RnrAiK  oi  ihk  iikaki:  In  wounds  of  the  heart  the 
muscle  fibres  take  no  part  in  the  process  of  re])air,  but  the  defect 
is  filled  by  granulation  tissue,  which  finally  forms  a  scar.  Adhesion 
to  the  pericardial  walls  is  common. 

Vm.  Repair  of  blood  vessels:  Wounds  of  vessels  of  large 
size  present  a  condition  somewhat  different  from  that  of  wounds 
of  other  tissues,  since  the  walls  contain  no  small  vessels  except  in 
the  adventitia  coat,  so  that  the  early  adhesion  of  the  edges  of  the 
wound  is  produced  not  by  an  inflammatory  exudate  in  the 
ordinary  sense  of  the  word,  but  is  due  to  fibrin  which  arises  from 
the  circulating  blood  in  the  vessel  itself.  The  conditions  vary 
somewhat  in  arteries  and  veins,  and  with  the  character  of  the 
injury,  i.e.,  whether  there  is  complete  division  of  the  vessel,  or  a 
lateral  wound,  or  a  rupture  of  the  internal  coat. 

In  arteries  com])lete  division  of  the  wall  by  a  sharp  instrument 
of  course  leads  to  violent  haemorrhage,  which  may  cause  death  in 
a  short  time.  In  complete  division  of  an  artery  by  tearing  or  by 
similar  violence,  however,  extensive  haemorrhage  as  a  rule  does 
not  take  place,  and  may  be  absent  even  in  clean  cuts,  because  the 
ends  of  the  vessel  retract  into  the  surrounding  tissues,  while  the 
walls  of  the  vessel  become  occluded  by  the  formation  of  a  clot, 
composed  of  fibrin  derived  from  the  blood  in  the  vessel,  enclosing 
red  blood  globules  and  a  few  leucocytes.  In  wounds  in  the  wall 
of  an  artery  the  haemorrhage  takes  place  into  the  soft  tissues 
about  the  point  of  injury,  and  coagulates,  so  that  finally  the  edges 
of  the  vessel   wound   are  sealed  together  by  a  layer  of  fibrin. 


25 


Within  the  lumen  of  the  vessel  may  be  simply  a  thin  peripheral 
clot  at  the  point  of  injury,  covering  the  wound  ;  or  in  other  cases, 
especially  if  the  endothelium  is  extensively  injured,  a  thrombus 
may  form,  of  such  size  as  to  occlude  the  vessel.  In  ligature  of  a 
completely  divided  vessel  a  clot  forms  at  the  point  of  ligature, 
the  size  of  which  is  variable,  de]:)ending  upon  the  rapidity  of  cir- 
culation, tne  amount  of  injury  to  the  endothelium,  and  the  per- 
fection of  asepsis. 

After  the  formation  of  the  thrombus  the  later  stages  are  like 
those  of  any  wound  ;  i.e.,  the  clot,  which  is  essentially  an 
inflammatory  exudate,  in  which  red  blood  globules  are  over- 
whelmingly predominant,  becomes  converted  into  organized  tissue. 
If  the  clot  is  a  small  one,  situated  peripherally,  the  surface  mav 
be  covered  by  newly-formed  endothelial  cells,  while  the  deeper 
layers  of  the  clot  are  replaced  by  newly-formed  connective  tissue 
derived  from  the  media  and  adventitia.  If  the  clot  is  of  large 
size  and  completely  fills  the  lumen  of  the  vessel,  the  surface  of 
the  clot  toward  the  blood  stream  is  covered  with  endothelium 
growing  from  the  walls  of  the  vessel,  while  the  clot  itself  becomes 
organized  by  granulation  tissue.  The  lumen  of  the  vessel  beyond 
the  point  of  obstruction  slowly  is  diminished  in  size  by  an  oblitera- 
tive  endarteritis. 

In  some  cases,  where  the  wound  in  the  vessel  is  a  lateral  one, 
a  large  clot  forms  about  the  point  of  injury,  pushing  apart  sur- 
rounding soft  tissues,  until  the  pressure  becomes  so  great  that  no 
further  hgembrrhage  takes  place.  The  effused  blood  coagulates, 
and  finally  the  periphery  may  become  organized  by  granulation 
tissue  arising  from  adjacent  connective  tissue.  In  some  cases 
the  centre  of  this  area  may  remain  patent  and  contain  fluid  blood, 
connected  with  the  circulating  blood  in  the  patent  vessel  through 
the  interval  in  the  wall  made  by  the  wound,  thus  forming  a  false 
traumatic  aneurism. 

In  complete  division  of  veins  the  divided  ends  usually  are  filled 
with  a  blood  clot  which  becomes  covered  by  endothelium,  while 
the  clot  itself  comes  to  be  replaced  by  dense  scar  tissue  derived 
from  the  media  and  adventitia.  In  some  cases  the  amount  of 
terminal  clot,  however,  is  exceedingly  small.  In  case  of  a  lateral 
wound  of  a  large  vein,  it  often  is  possible  to  prev'ent  severe 
haemorrhage  by  ligaturing  the  wound  in  the  vessel.  In  that  case 
the  inner  wall  of  the  veins  is  puckered  by  ligature,  and  may  be 
covered  with  a  thin,  peripherally  placed  clot,  which  may  become 


26 


organized  without  the  formation  of  an  obstructing  and  obliterating 
thrombus. 

In  all  lateral  wounds  of  vessels  absolutely  perfect  asepsis  is 
essential  if  one  expects  to  obtain  healing  without  complete  throm- 
bosis and  obstruction.  The  presence  of  even  a  slight  amount  of 
infection  is  practically  certain  to  cause  sufficient  injury  to  the 
endothelium  to  produce  complete  obstruction.  In  suturing  of 
vessels  it  is  said  that  the  projection  of  perfectly  aseptic  sutures 
into  the  lumen  of  the  vessel  through  the  endothelium  does  not 
necessarily  produce  thrombosis,  but  that  in  many  cases  the  sutures 
are  very  early  covered  with  new  endothelium. 

IX.  Peripheral  nervf>;  :  Section  or  destructive  injury  of  a 
peripheral  nerve  causes  an  immediate  traumatic  local  degenera- 
tion of  the  nei-ve  at  the  point  of  injury.  This  is  followed  by  a 
degeneration  throughout  the  extent  of  the  nerve  peripheral  to  the 
point  of  injury,  and  a  degeneration  of  the  fibres  proximal  to  the 
point  of  injury,  extending  no  farther  than  the  first  few  nodes  of 
Ranvier.  There  also  occur  changes  in  the  cells  of  origin  of  the 
degenerated  nerves,  resulting  in  an  effacement  of  the  granular 
structure  of  the  nerve  cell  body,  with  displacement  of  the  cell 
nucleus  to  the  periphery  of  the  cell,  the  so-called  "  axonal  reac- 
tion "  of  Nissl. 

Following  the  degeneration  occur  regenerative  changes  in  the 
nerve,  which  may  lead  to  a  restoration  of  function.  The  extent 
to  which  this  regeneration  may  occur  depends  somewhat  upon 
the  amount  of  injury  to  surrounding  soft  parts.  If  the  injury  is 
one  which  destroys  the  integrity  of  the  nerve  fibre,  without 
destroying  the  continuity  of  the  nerve  sheath,  e.g.,  crushing 
injuries,  the  regeneration  of  the  nerve  is  more  rapid  and  certain. 
If  the  nerve  is  cut  across  and  the  ends  are  sutured  together, 
regeneration  is  more  likely  to  occur  than  it  is  if  the  ends  retract 
and  become  widely  separated,  or  if  suppuration  occurs  so  that 
the  ends  are  separated  by  a  wide  zone  of  granulation  tissue.  If 
the  peripheral  end  of  a  nerve  is  entirely  removed,  as,  e.g.,  in  an 
amputation,  a  peculiar  partial  regeneration  of  the  proximal  por- 
tion may  occur,  resulting  in  an  "  amputation  neuroma." 

After  the  receipt  of  an  injury  there  comes  a  traumatic  degener- 
ation of  the  nerve  in  the  immediate  vicinity  of  the  injury.  The 
amount  of  this  degeneration  depends  upon  the  character  of  the 


27 


injury,  being,  ^'.t,'.,  slight  in  a  clean-cut  wound  and  more  extensive 
after  a  crush.  Immediately  after  this  change  there  comes  a 
secondary  ("paralytic")  degeneration  of  the  nerve,  extending  in 
either  direction  from  the  point  of  injury.  On  the  central  side  of 
the  injury  the  degeneration  extends  upward  to  the  nearest  nodes 
of  Ranvier.  On  the  peripheral  side  the  degeneration  extends 
throughout  the  entire  extent  of  the  nerve. 

The  degenerative  changes  produce  a  fragmentation  and  fibril- 
lation of  the  axis  cylinder,  and  a  fragmentation  of  the  medullary 
sheath.  Very  early  there  also  arises  marked  proliferation  of  the 
cells  in  the  sheath  of  Schwann. 

The  regenerative  process  begins  after  the  degenerative  process. 
It  is  difficult  to  say  just  how  the  new  axis  cylinders  are  produced, 
there  being  dispute  upon  this  point;  but  the  new  axis  cylinders 
extend  gradually  into  the  peripheral  end.  Most  observers  believe 
that  the  process  of  growth  is  like  that  in  embryological  develop- 
ment, I.e.,  a  constant  peripheral  growth.  Others  believe  that  the 
new  formation  is,  partly  at  least,  the  result  of  activity  of  cells  in 
the  sheath  of  Schwann.  As  a  practical  matter,  the  new  fibres  in 
the  adult  always  arise  from  the  central  stump  and  extend  periph- 
erally along  the  track  of  the  original  nerve. 

The  new  fibres,  as  they  arise  from  the  central  stump,  tend  to 
split  into  bundles  of  small  neuro-fibrils,  of  which  the  original 
nerve  is  supposed  to  be  composed.  The  direction  of  the  new 
fibres  may  be  modified  by  various  mechanical  obstructions,  and 
also  by  an  apparent  attraction  of  the  distal  nerve  remnant  for  the 
proximal  nerve  fibres.  The  fibres  at  first  grow  in  the  iijterstices 
between  the  cells  of  the  scar  ("neurotization  of  the  scar"), 
which  lies  between  ends  of  the  nerve.  If  the  scar  between  the 
ends  is  too  dense  the  new  fibres  may  grow  into  the.  tissues  in 
various  directions,  and  never  may  be  able  to  get  into  contact  with 
the  peripheral  stump.  In  such  cases  no  restoration  of  nerve 
function  takes  place.  The  tendency  of  the  proximal  axones  to 
join  the  peripheral  stump  can  be  favored  by  various  mechanical 
means,  e.g.,  catgut  sutures  along  the  tract  of  the  nerve,  or  hollow 
tubes,  or  neuro-plastic  flaps.  Regeneration  is  obstructed  by 
secondary  infection  with  excessive  formation  of  granulation 
tissue. 

The  rate  of  generation  varies  somewhat,  but  is  approximately 
at  the  rate  of  i  mm.  per  day. 


2M 


Cen'ir.al  nervous  svsiEM  :  As  regards  regeneration  or  repair  of 
injuries  to  the  central  nervous  system,  while  theoretically  possible 
to  a  very  slight  degree,  the  amount  of  regeneration  is  so  slight  as 
to  be  of  no  surgical  importance.  The  cause  of  the  lack  of 
power  of  central  nerves  to  regenerate  is  obscure,  but  it  is  claimed 
to  be  due  to  the  fact  that  the  central  nerve  fibres  do  not  possess 
a  sheath  of  Schwann,  which  is  essential  in  some  way  to  the  new 
formation  of  axis  cylinders,  and  also  to  the  fact  that  the  neurog- 
lia fibrils  offer  a  mechanical  obstruction  to  the  advance  of  nerve 
fibres. 

SUPPURATIVE    EXUD.VnONS. 

Under  certain  circumstances  leucocytes  may  be  jjresent  in 
enormous  numbers  in  exudate.  The  exudate  then  appears  thick, 
yellow,  and  creamy,  and  is  called  "  pus."  An  exudate  of  this 
sort  can  be  produced  experimentally  by  injecting  certain  chemi- 
cal substances  {e.g.,  croton  oil)  into  the  tissues  of  animals,  but 
in  human  beings  it  practically  always  is  due  to  infection  by  cer- 
tain microorganisms  ("pyogenic  bacteria").  These  bacteria 
produce  certain  soluble  substances  which  attract  leucocytes  in 
enormous  numbers,  and  a  cavity  may  be  formed  in  which  leuco- 
cytes and  tissue  products  are  containerl.  Such  a  cavity  is  an 
"abscess,"  and  may  open  upon  the  surface  of  the  body  by  a 
narrow  channel  ("sinus").  If  the  surface  of  such  an  abscess 
cavity  is  destroyed  so  that  an  open  sore  is  j^roduced,  an  "  ulcer  " 
is  formed.  The  process  just  described  is  spoken  of  as  "  frank" 
suppuration. 

In  other  cases  the  organisms  produce  extensive  necrosis  and 
suppuration,  without  marked  solution  of  tissue.  The  organisms 
then  tend  to  extend  along  the  lymphatic  vessels  ("  lymphangitis  "), 
or  along  the  connective  tissue  septa  ("phlegmon,"  "  cellulitis  "). 
In  that  case  the  process  is  spoken  of  as  "  diffuse  "  suppu- 
ration. 

Typical  frank  suppuration  is  produced  by  the  staphylococcus 
aureus.  Typical  diffuse  su])puration  is  produced  by  the  strepto- 
coccus. 

Acute  suppurative  inflammation  may  extend  to  and  involve  the 
adjacent  blood  vessels,  causing  coagulation  of  the  blood  ("throm- 
bus"). Such  a  thrombus  contains  pyogenic  organisms.  Frag- 
ments of  such  a  thrombus  may  be  torn  off  (embolus)  and  carried 
into  the  general  circulation,  and  lodge  in  distant   parts  of  the 


29 


body.     Such  emboli,  since  they  contain  infected  organisms,  may 
act  as  the  secondary  foci  of  suppuration  ("  metastases  "). 

AnscESS  KOKMA'j'ioN  :  Frank  suppuration  of  the  type  produced 
by  staphylococcus  aureus.  The  furuncle  and  carbuncle  may  be 
taken  as  examples  of  this  type  of  inflammation. 

Furuncle :  A  furuncle  is  an  acute  suppuration  of  the  skin  and 
subcutaneous  tissues,  which  develops  about  a  hair  follicle  or 
sebaceous  gland. 

Under  certain  conditions  the  staphylococcus  aureus  may  obtain 
access  to  the  subcutaneous  tissue  through  the  unbroken  skin 
along  a  hair  follicle.  Having  invaded  the  tissues  the  coccus 
produces  a  soluble  toxin  which  causes  necrosis  of  adjacent  tissues. 
Into  the  necrotic  area  comes  exudation.  By  action  of  the  toxin 
the  necrotic  tissue  is  dissolved,  so  that  a  cavity  is  formed  con- 
taining exudate,  bits  of  necrotic  tissue,  and  very  little  fibrin,  i.e., 
"  abscess."  About  this  abscess  cavity  comes  proliferation  of  ad- 
jacent connective  tissue  and  formation  of  new  vessels.  This  layer 
of  granulation  tissue  is  the  so-called  "  pyogenic  membrane."  If 
the  cocci  continue  to  develop  this  pyogenic  membrane  may,  in 
turn,  become  necrotic  and  dissolve,  so  that  the  abscess  enlarges, 
while  granulation  tissue  continues  to  form  about  the  enlarged  ab- 
scess. If  the  process  last  for  any  length  of  time  lymphoid  and 
plasma  cells  are  seen  in  the  surrounding  granulation  tissue.  The 
process  continues  until  the  cocci  lose  their  virulence,  or  the  con- 
tents of  the  abscess  are  evacuated.  After  the  contents  are 
removed  granulation  tissue  grows  into  and  fills  the  cavity,  while 
the  epitheUum  about  the  opening  proliferates  and  covers  it.  At 
length  the  granulation  tissue  is  converted  into  dense  fibrous 
tissues,  and  forms  a  scar. 

Gross  appearances  :  A  pustule  appears  about  the  base  of  a 
hair.  In  a  few  hours  the  pustule  is  surrounded  by  a  circum- 
scribed dark  red  swelling,  hot  and  painful.  From  the  fifth  to  the 
seventh  day  a  yellow  softened  area  appears  at  the  apex  of  this 
swelling,  /.c,  the  furuncle  "  points."  Through  this  opening  is 
discharged  a  mass  of  yellow,  necrotic  material  ("  slough  "),  leav- 
ing a  cavity  lined  with  granulation  tissue.  In  a  few  days  after 
the  furuncle  is  evacuated  the  cavity  is  filled  by  granulation  tissue, 
while  the  surface  is  covered  with  proliferated  epidermis.  The 
entire  process  takes  about  two  weeks.  The  granulation  tissue 
finally  is  converted  into  dense  fibrous  tissue,  and  forms  at  first  a 
reddened  and  later  a  white  scar. 


:io 


Carbuncle :  A  carbuncle  is  a  suppuration  of  the  skin  and  sub- 
cutaneous tissues,  similar  in  character  to  the  furuncle,  but  usually 
more  extensive  and  severe,  and  modified  somewhat  by  the  anat- 
omy of  the  skin  in  certain  parts  of  the  body.  In  some  portions 
of  the  body  the  subcutaneous  tissues  are  very  thick,  and  the  hair 
follicles  extend  only  part  way  through  it.  Extending  downward 
from  the  base  of  these  hair  follicles  are  clefts  in  the  true  skin. 
These  clefts  are  filled  with  fat  ("columnae  adiposae").  From 
the  sides  of  the  base  of  these  columnae  strong  bands  of  fibrous 
tissue  extend  to  the  underlying  fascia,  binding  the  skin  firmly  to 
the  fascia.  The  staphylococcus  aureus  is  the  common  cause  of 
carbuncle. 

The  staphylococcus  probjbly  obtains  access  to  the  subcuta- 
neous tissues  along  the  hair  follicles.  Having  reached  the  sub- 
cutaneous tissue,  the  process  is  the  same  as  in  the  furuncle  — 
necrosis,  infiltration  with  leucocytes,  and  solution.  Because  of 
the  firm  adhesion  of  the  skin  to  the  underlying  fascia  by  the 
fibrous  bands  already  described,  the  extension  of  the  process  lat- 
erally is  not  easy,  so  it  extends  along  the  line  of  least  resistance, 
i.e.,  into  the  columnae  adiposae  to  the  base  of  the  adjacent  hair 
follicles,  and  from  these  to  the  surface  of  the  skin.  In  this  way 
numerous  secondary  areas  of  suppuration  are  formed  upon  the 
surface.  By  continuation  of  this  process  and  fusion  of  adjacent 
foci  a  large  central  area  of  necrosis  is  formed,  surrounded  by 
secondary  smaller  areas,  due  to  extension  from  below. 

About  the  necrotic  area  comes  marked  proliferation  with  pro- 
duction of  granulation  tissue.  After  the  process  ceases  to  extend, 
the  necrotic  tissue  dissolves  and  is  separated  from  the  underly- 
ing granulation  tissue,  leaving  a  more  or  less  extensive,  frequently 
very  deep  ulcer.  Ultimately  this  ulcer  is  filled  in  by  granulation 
tissue,  while  the  surface  of  the  ulcer  is  covered  by  proliferated 
epidermis. 

Gross  appearances  :  The  carbuncle  appears  as  a  diffuse,  brawny 
swelling,  generally  upon  the  neck  or  back ;  bluish-red  at  the 
centre,  and  a  brilliant  red  at  the  periphery.  In  the  centre  appear 
numerous  yellow,  soft  points  usually  one  large  one  in  the  centre, 
surrounded  by  small  ones.  Ultimately  these  yellow  areas  enlarge 
and  coalesce,  forming  a  large  yellow  slough  in  the  centre  of  the 
area.  After  some  time  this  slough  dissolves  and  is  cast  off,  leav 
ing  a  large  granulating  wound  which  closes  by  granulation. 


31 


DiFFUSF,  suppuration:  "  FhlcgtHoii,'"  ''Lymphangitis^'  is  a 
diffuse  acute  suppuration  of  the  skin  and  subcutaneous  tissues, 
generally  secondary  to  some  wound  of  the  skin.  It  generally  is 
due  to  infection  by  the  streptococcus  pyogenes. 

The  infection  extends  along  the  line  of  lymph  vessels  and 
connective  tissue  clefts.  The  organisms  produce  necrosis  and 
exudation.  The  subcutaneous  tissue  early  becomes  necrotic, 
often  over  enormous  areas,  but  solution  of  the  tissue  is  much  less 
marked  than  in  abscess  formation,  although  some  localized  areas 
of  solution  may  appear.  If  the  infection  is  mild  the  exudation 
soon  is  absorbed,  the  necrotic  tissue  is  dissolved  and  absorbed, 
and  the  area  occupied  by  the  necrotic  tissue  becomes  filled  with 
granulation  tissue,  which  ultimately  becomes  dense  fibrous  tissue, 
so  that  the  skin  becomes  firm,  hard,  and  adherent,  and  may 
cause  much  impairment  of  function  of  underlying  muscles.  Some- 
times the  necrosis  involves  the  superficial  layers  of  the  skin,  and 
the  necrotic  area  may  be  separated  from  the  underlying  granula- 
tion tissue  in  the  form  of  an  extensive  slough,  leaving  behind  a 
wound  which  closes  by  granulation. 

Gross  appearances  :  If  the  infection  is  confined  at  first  to  the 
lymph  vessels  (lymphangitis)  dark  red  lines  appear,  extending 
from  the  infected  wound  along  the  line  of  lymph  vessels.  The 
lymph  nodes  along  the  line  of  the  lymphatics  become  infected, 
enlarged,  and  are  tender.  If  the  infection  persist,  in  the  course 
of  a  few  hours  the  tissue  becomes  diffusely  reddened  and  swollen, 
and  is  tender  and  pits  on  pressure.  The  lymph  nodes  may 
break  down  and  form  an  abscess  at  a  considerable  distance  from 
the  original  point  of  infection. 

If  the  infection  (primarily)  extends  along  the  connective  tissue 
septa,  redness  and  swelling  are  seen  about  the  infected  wound, 
and  the  skin  pits  on  pressure.  This  area  of  exudation  enlarges 
peripherally,  and  may  extend  over  enormous  areas.  If  the  infec- 
tion is  very  severe,  blebs  and  bullae  filled  with  pus  appear  on  the 
surface.  In  certain  cases  the  superficial  layers  of  the  skin  are 
involved,  and  skin  and  subcutaneous  tissue  may  be  cast  off  as  a 
slough,  leaving  a  dirty  grayish  surface  behind.  In  cases  which 
do  not  go  on  to  ulceration,  if  the  tissue  is  incised  during  the 
acute  stage  a  thin  fluid  escapes,  while  the  subcutaneous  tissue  is 
yellow,  gelatinous,  and  the  skin  is  porky. 

The  process  may  quiet  down  in  a  few  days,  leaving  the  skin 
reddened,  firm,  and  adherent  to  the  underlying  tissues  from  the 


32 


formation  of  granulation  tissue.  In  severer  forms,  after  the  slough 
is  separated,  a  more  or  less  extensive  granulating  wound  is  left, 
which  heals  like  other  granulating  wounds. 

Erysipelas  is  an  acute  inflammation  of  the  skin  and  subcutane- 
ous tissue,  usually  due  to  infection  of  large  or  microscopic 
wounds.  Rarely  it  may  be  due  to  infection  of  the  hair  follicles. 
The  process  is  due  to  infection  by  a  streptococcus,  probably 
identical  with  the  streptococcus  pyogenes  which  produces  phleg- 
mon. The  process  in  general  is  the  same  as  that  in  phlegmon, 
but  the  infection  generally  is  more  superficial. 

Gross  appearances  :  Erysipelas  appears  as  a  localized  redness, 
glazing,  and  swelling  of  the  skin.  The  exudation  may  persist  for 
a  time  in  one  place  and  then  extend  to  adjacent  regions.  In 
severe  cases  blebs  and  pustules  may  appear  on  the  surfoce,  and 
portions  of  the  skin  may  become  necrotic  and  gangrenous.  As  a 
rule,  the  skin  returns  to  its  normal  condition,  and  the  formation 
of  connective  tissue  is  slight,  unless  necrosis  and  gangrene  have 
occurred. 

Principles  of  treatment. 

Abscess  :  In  some  cases  of  acute  superficial  abscess  of  the  skin 
it  is  possible  to  "  abort  "  the  abscess  by  injection  of  strong  aseptic 
fluid,  e.g.,  carbolic  acid.  In  all  abscesses  the  chief  essential  is 
opening  and  drainage  of  the  purulent  fluid.  In  carbuncles  com- 
plete excision  often  is  the  best  method  of  treatment. 

Phlegmon  :  Incision  and  drainage  are  indicated. 

Erysipelas :  On  account  of  the  wandering  character  of  the 
disease  incision  is  useless. 

OSTEOMYELITIS 

is  acute  suppuration  of  bone,  due  to  infection  by  pathogenic 
microorganisms,  generally  the  staphylococcus  aureus.  It  has  been 
designated  "  furunculosis  "  of  bone. 

Cause  :  The  staphylococcus  aureus  is  the  organism  most  com- 
monly present.  Sometimes  other  organisms,  streptococcus, 
pneumococcus,  and  typhoid  bacillus,  produce  the  disease. 
Certain  factors  predispose  to  the  disease.  It  occurs  generally  in 
young  adults  or  children.  Exposure  to  cold  and  fatigue  often 
precede  the  attack.  The  disease  frequently  occurs  subsequent  to 
acute  infectious  disease,  e.g.,  typhoid  fever,  scarlet  fever,  etc.  In 
these  cases  the  process  generally  is  due  to  a  secondary  infection 


33 


with  pyogenic  organisms,  but  sometimes  is  due  to  primary  infec- 
tion by  the  specific  organism,  e.t^.,  "typhoid  osteomyelitis."  The 
disease  often  is  secondary  to  suppuration  elsewhere,  e.g.,  furuncle. 
Frequently  after  compound  fractures  the  injured  ends  are  in- 
fected by  microorganisms,  and  "  traumatic  osteomyelitis  "  results. 

Process  :  The  infection  always  begins  in  the  marrow  of  bone. 
The  trabecular  and  cortical  portions  are  destroyed  secondarily. 
The  disease  begins  almost  always  in  the  diaphysis  of  a  bone, 
often  near  the  epiphyseal  line.  The  process  may  begin  rarely  in 
the  epiphysis  and  extend  to  and  destroy  the  joint. 

If  the  organisms  obtain  access  to  the  marrow  they  produce  a 
toxin  which  causes  necrosis  of  marrow  cells.  Since  the  marrow 
spaces  communicate  freely  with  each  other  the  toxic  material  is 
retained,  and  so  necrosis  may  be  very  extensive  before  infiltration 
with  exudate  is  marked.  The  marrow  tissue  then  appears 
necrotic  over  large  areas,  and  throughout  the  necrosis  are  numer- 
ous colonies  of  cocci.  Exudation  follows,  and  is  chiefly  leuco- 
cytes. Solution  of  marrow  cells,  often  over  considerable  areas, 
may  occur.  Sometimes  there  is  more  or  less  solution  of  bony 
trabeculas,  so  that  a  cavity  is  formed  containing  leucocytes  and 
tissue  detritus,  "bone  abscess."  The  process  may  extend  along 
the  marrow  spaces  and  involve  the  marrow  of  the  entire  shaft  in 
a  very  short  time.  The  infection  generally  extends  through  cor- 
tical bone  to  the  periosteum.  In  that  case  the  periosteum  may 
be  stripped  and  elevated  from  the  bone  over  a  large  area.  Be- 
tween the  bone  and  periosteum  a  purulent  exudate  is  present, 
often  in  considerable  amount.  The  infection  may  extend  to  the 
soft  tissues  and  cause  necrosis  and  suppurative  inflammation,  and 
result  in  the  formation  of  an  abscess,  often  very  extensive,  con- 
necting with  the  bone.  The  abscess  may  extend  to  the  surface, 
involve  the  skin,  and  open  and  discharge  through  one  or  more 
sinuses.  The  process  usually  does  not  extend  beyond  the  epi- 
physeal line,  but  may  cause  separation  of  the  epiphysis  (sponta- 
neous fracture),  or  even  extend  to  and  destroy  the  epiphysis.  I 
the  epiphysis  is  involved  the  infection  may  extend  to  the  joint 
cavity,  produce  suppuration  and  destruction  of  the  joint.  Gen- 
eral infection,  toxaemia,  and  metastasis  may  occur  early  in  the 
disease. 

Repair  :  The  reparative  process  which  follows  suppuration  pro- 
duces certain  peculiar  gross  conditions.  In  the  marrow  spaces 
granulation  tissue  forms,  is  converted  into  scar  tissue,  and  walls 


34 


off  the  necrotic  portion  from  the  healthy  portion  of  the  shaft. 
The  periosteum  Ijccomes  separated  from  the  underlying  necrotic 
shaft  (sequestrum)  and  forms  a  layer  of  new  jjeriosteal  bone, 
which  surrounds  the  original  shaft  as  a  more  or  less  complete 
shell  (involucrum). 

Proliferation  of  the  connective  tissue  of  the  marrow  begins  in 
a  few  days.  Since  the  marrow  spaces  open  out  into  each  other 
in  an  irregular  way  a  microscopic  section  may  show  adjacent 
spaces,  in  one  of  which  is  necrotic  tissue  and  exudate,  while  an 
adjoining  one  is  filled  with  granulation  tissue.  Granulation  tissue 
may  fill  up  marrow  spaces  and  attempt  to  encapsulate  the  in- 
flamed area,  or,  if  one  entire  end  of  the  shaft  is  necrotic,  may 
extend  across  the  shaft  and  form  a  layer  of  granulation  tissue 
separating  the  necrotic  from  the  sound  portion  of  the  shaft.  The 
granulation  tissue  shows  extremely  numerous  lymphoid  and 
plasma  cells.  In  time  the  granulation  tissue  becomes  dense  "scar 
tissue,  separating  the  necrotic,  loosened  end  of  the  shaft.  If  the' 
entire  diaphysis  has  been  involved  in  the  original,  granulation  tis- 
sue may  develop  in  some  portions  and  not  in  others,  so  that 
some  of  the  marrow  spaces  are  filled  with  exudate,  others  with 
granulation  tissue,  giving  a  peculiar  mottled  appearance  of  yellow 
and  red  to  the  bone  on  section.  Walling  off  of  the  necrotic 
shaft  may  take  from  two  to  several  months. 

The  periosteum  proliferates  early.  At  first  it  forms  a  thickened 
layer  like  granulation  tissue.  In  the  course  of  a  few  weeks  new 
trabecule  appear,  like  those  in  the  external  callus  of  a  fracture 
(see  Fractures).  By  the  end  of  eight  to  sixteen  weeks  this 
layer  of  new  periosteal  bone  is  of  considerable  thickness  (^^ 
inch).  In  the  course  of  months  this  bone  thickens,  becomes 
bone  like  cortical  bone,  and  surrounds  the  original  shaft  like  a 
shell  "  involucrum,"  and  becomes  separated  from  the  original 
shaft,  which  also  is  separated  from  the  healthy  portion  of  the 
shaft.  The  loose  fragment  of  the  original  shaft  may  persist  as  a 
"  sequestrum,"  and  lies  in  a  cavity  lined  with  granulation  tissue, 
forming  an  open  sore  which  may  discharge  for  years ;  or  the 
sequestrum  may  be  disintegrated  and  discharged  piecemeal 
through  sinuses.  If  the  sequestrum  is  removed,  artificially  or 
naturally,  it  leaves  a  cavity  lined  with  granulation  tissue,  sur- 
rounded by  dense  cortical  bone,  which  shows  very  little 
tendency  to  heal,  and  may  persist  for  years. 

Gross  aj)pearances  :  At  first  the  infected  bone  may  show  no 


35 


visible  change  beyond  intense  local  pain.  If  the  process  extends 
to  the  periosteum  and  soft  tissues  it  produces  enormous  deep 
swelling  with  redness  and  pitting  on  pressure.  If  the  abscess 
extend  towards  the  surface,  fluctuation  may  appear.  The  abscess 
may  point  at  one  or  more  places  and  break  through  the  skin  and 
discharge  its  contents  through  one  or  several  sinuses.  After 
evacuation  of  the  contents  of  the  abscess  the  shaft  appears 
nearly  of  normal  thickness.  In  a  few  weeks  the  shaft  appears 
appreciably  greater  in  thickness,  due  to  the  formation  of  the 
periosteal  shell.  At  the  end  of  twelve  to  sixteen  weeks  the  peri- 
osteum is  about  y'jT  of  an  inch  thick  and  contains  thin  plates  of 
periosteal  bone.  In  a  few  weeks  more  (sixteen  to  thirty  weeks) 
the  periosteal  shell  becomes  thick  enough  to  take  on  the  function 
of  the  original  shaft.  The  original  shaft  during  this  time  may  be 
felt  as  a  shaft  of  bare  bone.  In  time  it  becomes  loosened  and 
may  be  removed  by  operation,  or  may  be  discharged  spontane- 
ously through  sinuses. 

At  any  of  these  stages,  i.e.,  early  necrosis,  early  periosteal  pro- 
liferation, or  in  the  stage  of  involucrum  and  sequestrum,  it  is 
possible  to  take  advantage  of  the  regenerative  power  of  the  peri- 
osteum and  endosteum  to  bring  about  complete  regeneration  of 
bone. 

In  all  cases  it  first  is  necessary  to  remove  the  necrotic  bone, 
which  acts  as  a  foreign  body.  After  the  necrotic  bone  is  removed 
the  intact  periosteum  should  be  approximated  so  as  to  bring  the 
internal  surfaces  together  and  to  leave  no  central  cavity.  The 
growth  of  the  periosteum  is  peripheral,  and  new  bone,  like  the 
external  callus,  is  formed,  until  a  shaft  of  periosteal  bone  is  pro- 
duced which  slightly  exceeds  in  size  that  of  the  original  shaft. 
As  the  bone  becomes  harder  as  it  grows  older,  there  is  some 
absorption  of  the  bone,  until  ultimately  the  new  bone  is  of  the 
same  size  as  the  original  shaft.  The  new  bone  at  first  is  solid 
bone  without  a  marrow  canal,  but  finally,  judging  from  X-ray  pict- 
ures, there  is  an  absorption  of  the  bone  in  the  centre  of  the  shaft, 
and  a  new  marrow  canal  is  formed.  The  notable  thing  about 
this  process  of  bone  regeneration  by  the  periosteum  is  that  the 
new  bone  is  of  exactly  the  same  shape  as  the  original  bone,  and 
cannot  be  distinguished  even  by  touch,  sight,  or  the  X-ray.  This 
suggests  that  the  shape  of  the  bones  of  the  human  skeleton  is  due 
to  two  causes  —  heredity,  and  environment  or  function.  Hence, 
when  a  bone  is  removed  the  new  bone  which  is  formed  is  of  the 


^^] 


shape  which  performs  function  to  the  best  advantage.  This  is 
true  of  very  complicated  bones,  and  even  of  complicatetl  joints 
which  are  excised  subperiosteally. 

In  some  cases  where  the  involucrum  is  old  it  has  limited  power 
of  repair  and,  in  such  cases,  both  involucaim  and  .sequestrum 
must  be  removed  to  give  the  periosteum  a  chance  to  form  an 
entirely  new  bone. 

This  theoretically  ideal  method  of  repairing  destruction  caused 
by  acute  suppuration  in  bone  is  not  always  practicable  for  various 
surgical  reasons.  In  some  cases  it  is  better  to  employ  aseptic 
blood  clot,  or  osteoplastic  bone  flaps,  or  curettage  and  skin 
grafting. 

APPENDICniS. 

Acute  suppuration  of  the  vermiform  appendix  is  the  most 
common  cause  of  peritonitis  in  men,  and  is  a  frequent  cause  of 
peritonitis  in  women. 

Etiology  :  The  process  probably  is  due  to  infection  by  pyogenic 
organisms  of  a  superficial  necrosis  of  the  mucous  membrane  of 
the  appendix.  The  cause  of  the  primary  necrosis  frequently  is 
f?ecal  concretions,  rarely  foreign  bodies  (t'.,i(.,  pin,  intestinal  para- 
sites, fishbones,  etc.).  The  organism  that  infects  the  necrosis  is 
in  90  per  cent,  of  the  cases  the  streptococcus  pyogenes.  Cult- 
ures taken  from  appendiceal  abscesses  always  show  a  profuse 
growth  of  the  colon  bacillus,  and  pyogenic  organisms  may  not 
develop.  If  fresh  smears  from  the  abscess  are  examined,  how- 
ever, streptococci,  frequently  dead,  are  found.  Pure  cultures  of 
the  colon  bacillus  injected  into  the  peritoneum  of  animals  do  not 
cause  peritonitis.  So  it  is  probable  that  the  original  infection  in 
these  cases  is  due  to  the  streptococcus,  and  the  organism  does 
not  appear  in  cultures  because  it  is  crowded  out  by  the  resistant 
colon  bacillus. 

Process  :  Superficial  necrosis  or  lowered  resistance  of  appendi- 
ceal mucous  membrane  is  caused  by  frecal  concretions  or  other 
foreign  bodies.  Infection  by  pyogenic  organisms,  generally  the 
streptococcus,  takes  place.  The  infection  produces  necrosis  and 
acute  exudation  in  the  wall  of  the  appendix.  The  infection  may 
extend  through  the  wall  of  the  appendix,  and  cause  a  localized 
infection  of  the  adjacent  peritoneum,  without  perforation ;  usually 
the  necrosis  produces  sloughing  and  perforation  of  the  wall  of  the 
appendix.     The  perforation  may  be  small  or  large,  and  occur  at 


37 


the  tip  or  near  the  csecal  attachment ;  or  the  entire  appendix  may 
become  gangrenous  and  slough.  Perforation  of  the  appendix 
allows  extravasation  of  intestinal  contents  and  a  local  or  general 
infection  of  the  peritoneum  (extravasation  peritonitis). 

If  the  perforation  is  small  and  takes  place  near  the  tip  the 
amount  of  extravasation  usually  is  small,  and  the  resulting  peri- 
tonitis is  circumscribed.  As  a  result  of  the  peritonitis  a  fibrin- 
ous or  fibrino-purulent  exudate  is  formed  upon  the  surface  of  the 
appendix  and  intestines.  This  exudate  binds  together  folds  of 
adjacent  intestine,  and  may  "wall  off"  the  perforated  appendix 
from  the  general  peritoneal  cavity  (appendiceal  "cake").  An 
abscess  may  form  about  the  appendix,  surrounded  by  coils  of 
adherent  intestine.  Such  an  abscess  may  burst  through  the 
adhesions  and  infect  the  general  peritoneal  cavity.  If  the 
process  subsides  fibrinous  adhesions  become  organized  and 
fibrous  bands  fasten  coils  of  intestine  firmly  together.  The  exu- 
date upon  the  surface  of  the  appendix  may  become  organized 
and  increase  the  size  of  the  organ  to  an  enormous  extent. 

If  the  perforation  is  large  and  near  the  csecal  attachment,  or  if 
the  entire  appendix  becomes  gangrenous,  a  very  extensive  extra- 
vasation of  faecal  contents  may  take  place  in  a  very  few  hours. 
This  may  take  place  so  rapidly  that  adhesions  may  be  unable  to 
wall  off  the  appendix  and  a  general  infection  of  the  peritoneal 
cavity  may  occur.  Such  cases  of  general  peritonitis  usually  are 
fatal. 

During  the  acute  stage  the  mucous  membrane  of  the  appendix 
shows  more  or  less  extensive  areas  of  necrosis,  exudation,  and 
ulceration.  The  lumen  of  the  appendix  is  filled  with  purulent 
exudate.  All  the  coats  of  the  appendix  are  infiltrated  with  exu- 
date. Upon  the  serous  surface  is  an  exudate,  largely  fibrinous. 
If  the  attack  subside  the  ulcer  heals,  the  walls  become  thickened 
by  formation  of  granulation  tissue,  and  infiltrated  with  lymphoid 
and  plasma  cells.  The  exudate  on  the  serous  surface  is  replaced 
by  granulation  tissue.  In  time  the  walls  are  thickened  from  the 
presence  of  dense  fibrous  tissue  and  the  appendix  is  surrounded 
by  a  more  or  less  extensive  layer  of  dense  fibrous  tissue. 

Gross  appearances  :  During  the  early  hours  the  appendix  is 
injected  and  swollen  from  the  presence  of  exudate.  On  the  sur- 
face is  a  layer  of  exudate.  The  wall  may  show  a  small  or  large 
perforation.  About  the  appendix  may  be  adherent  coils  of 
injected  intestine ;  or  an  abscess,  often  very  extensive,  filled  with 


38 


foul  yellow  or  hnemorrhagic  pus,  forms  about  the  appendix,  shut 
off  from  the  general  peritoneal  cavity  by  folds  of  inflamed  intes- 
tine. If  the  process  is  very  severe  the  appendix  may  slough  fii 
r/iassf  and  lie  in  the  abscess  cavity,  or  entirely  disappear.  If  the 
attack  subside  the  appendix,  much  thickened  by  organized  tissue, 
may  be  surrounded  by  folds  of  intestine,  firmly  bound  together  by 
bands  of  granulation  tissue,  which  in  time  become  dense  fibrous 
tissue.  If  infection  of  the  general  peritoneal  cavity  take  place 
during  the  acute  attack,  all  abdominal  viscera  are  injected, 
covered  with  a  very  extensive  layer  of  fibrino-purulent  or  purulent 
exudate,  yellow,  green,  or  hsemorrhagic.  Much  free  pus  may 
collect  in  certain  portions  of  the  abdomen.     Gas  often  is  present. 

Tubercular  appendix :  In  tuberculosis  of  the  intestinal  tract 
the  appendix  may  become  infected.  Tubercular  ulceration  may 
cause  perforation  of  the  appendix  with  extravasation  of  frecal  con- 
tents, but  is  ver}'  rare. 

Characteristic  tubercular  lesions  are  seen  in  the  wall  of  the 
appendix. 

Typhoid  appendix  :  Occasionally  in  typhoid  fever  ulceration 
and  perforation  of  the  appendix  occurs.     \'ery  rare. 

Principles  of  treatment :  In  some  cases  it  is  possible  to  re- 
move a  diseased  appendix  before  acute  suppuration  occurs.  If 
acute  suppuration  does  occur  it  is  to  be  treated  like  other 
abscesses,  i.e.,  by  drainage,  with  removal  of  the  appendix.  In 
some  cases  if  the  acute  suppuration  subsides  it  is  possible  to  re- 
move the  appendix  during  the  quiescent  stage,  i.e.,  "  between  the 
attacks."  If  general  infection  of  the  peritoneal  cavity  occurs  it 
must  be  treated  like  any  general  peritonitis. 

TUBERCULOSIS   OF   THE    BONES   AND   JOINTS. 

Cause  :  Infection  of  the  marrow  of  the  bone  by  the  tubercle 
bacillus.  The  identity  of  the  disease  with  other  tuberculous 
tissues  is  proven  by  the  presence  of  miliary  tubercles  containing 
the  tubercle  bacillus,  by  inoculation  of  animals  with  bone,  soft 
tissue  from  joints  or  wall  of  a  cold  abscess,  producing  tuberculosis 
in  susceptible  animals,  and  by  the  experimental  production  of 
joint  lesions  in  animals,  similar  to  those  produced  in  human 
beings.  Certain  causes  favor  the  occurrence  of  tuberculosis  of 
bone.  It  occurs  chiefly  in  early  youth.  Trauma  of  moderate 
severity,  e.^'-,  sprains,  often  precedes  joint  lesions.  Tuberculous 
joints  usually  are  secondary  to  old  tuberculous  foci  and  tubercular 


39 


disease  elsewhere  in  the  body ;  ^.,i,^,  bronchial  or  mesenteric 
lymph  nodes.  Primary  disease  of  the  bones  occurs  rarely  ;  of  the 
joints,  almost  never. 

The  tubercle  bacillus,  having  obtained  access  to  the  bone  mar- 
row, causes  the  formation  of  miliary  tubercles  which  arise  by 
proliferation  of  the  connective  tissue  of  the  marrow.  As  the 
tubercles  enlarge,  the  centre  becomes  caseous,  and  by  fusion  of 
caseous  areas  an  area  of  softening  is  produced  in  the  bone.  The 
trabeculre  at  first  are  not  involved,  but  at  length  may  soften  and 
break  down,  forming  a  cavity  (tuberculous  abscess)  in  the  bone. 

Bones  :  In  the  /o^i^'-  bones  tuberculous  disease  begins  almost 
invariably  in  the  marrow  of  an  epiphysis,  never  in  the  cartilage, 
and  very  rarely  ii;  the  diaphysis.  By  coalescence  and  caseation 
of  tubercles  the  marrow  is  destroyed,  often  in  considerable  areas. 
If  the  trabecule  in  such  an  area  dissolve,  a  cavity  is  formed 
(tuberculous  bone  abscess).  In  other  cases  the  trabecule  retain 
their  shape,  while  the  marrow  spaces  are  filled  with  tuberculous 
necrotic  tissue  ;  i.e.,  a  "  tuberculous  sequestrum  "  is  formed.  In 
the  marrow  spaces  surrounding  either  abscess  or  sequestrum  is  a 
formation  of  granulation  tissue.  The  tuberculous  area  enlarges 
peripherally,  extends  towards  the  surface,  and  may  open  upon  the 
surface  (very  rare)  or  into  the  adjacent  joint  (usual). 

In  the  s/wr/  long  bones,  e.g.,  the  phalanges,  the  process  may 
begin  in  the  diaphysis.  The  entire  shaft  may  become  tubercu- 
lous, while  the  periosteum  proliferates,  as  in  the  case  of  osteo- 
myelitis {q.v.),  and  forms  a  new  bony  shell.  As  a  result,  the  shaft 
enlarges,  becomes  spindle-shaped,  while  the  tuberculous  process 
may  open  upon  the  surface  by  various  sinuses  (spina  ventosa). 

In  the  short  bones  the  tubercles  often  destroy  an  entire  bone, 
and  secondarily  invade  several  adjacent  bones  and  joints  at  a 
comparatively  early  period. 

Tuberculous  disease  of  the  flat  bones  is  less  frequent,  but  not 
uncommon.  The  cranial  bones  frequently  are  attacked.  No 
bone  in  the  body  is  exempt. 

General  miliary  tuberculosis  of  the  bones  occurs  in  cases  of 
acute  miliary  tuberculosis.  In  that  case  the  miliary  tubercles  are 
seen  scattered  throughout  the  marrow,  but  they  never  attain  a 
size  sufficient  to  cause  clinical  symptoms. 

Adsi'ess  :  "  Cold  Abscess."  If  tubercular  disease  extends  from 
the  bones  to  the  adjacent  soft  tissues,  tubercles  form,  enlarge, 
become  caseous,  and  coalesce  and  form  a  cavity  which  contains 


40 


necrotic  tuberculous  material,  serum,  and  comparatively  few 
leucocytes  ("  cold  abscess  ").  About  such  an  abscess  is  a  layer 
of  tuberculous  tissue,  composed  either  of  discrete  miliary  tuber- 
cles or  of  a  layer  of  diffuse  ulcerating  tuberculous  tissue.  Sur- 
rounding this  tuberculous  tissue  is  a  layer  of  reactionary  granulation 
tissue.  Such  an  abscess  may  open  upon  the  surface  of  the  body 
by  a  sinus  which  connects  with  the  abscess  cavity.  The  lining  of 
the  sinus  is  tuberculous  tissue,  like  that  which  lines  the  abscess. 

Joints:  Primary  tuberculous  disease  of  the  joint  occurs  seldom 
or  never,  and  tuberculosis  of  the  joint  almost  invariably  is  second- 
ary to  tuberculous  disease  of  the  adjacent  epiphysis.  As  the 
tubercular  focus  in  the  epiphysis  enlarges,  it  extends  towards  the 
cartilage  which  covers  the  end  of  the  bone.  The  cartilage 
becomes  fibrillated  and  finally  perforated  at  one  or  more  points. 
The  tubercle  bacillus  is  diffused  throughout  the  synovial  fluid. 
The  tubercle  bacilli  are  taken  into  the  lymphatic  spaces  of  the 
synovial  membrane  and  produce  miliary  tubercles.  By  enlarge- 
ment, fusion,  and  caseation  of  these  tubercles  the  surface  of  the 
synovial  membrane  becomes  covered  with  tuberculous  ulcers. 
From  the  attachment  of  the  synovial  membrane  to  the  cartilage 
the  tuberculous  tissue  extends  over  and  beneath  the  cartilage 
which  covers  the  ends  of  the  bones  (tuberculous  "pannus"). 
Wherever  the  cartilage  comes  in  contact  with  this  tuberculous 
tissue  it  becomes  fibrillated  and  ultimately  destroyed.  As  a 
result,  the  cartilage  may  be  perforated  at  various  points,  or  lifted 
from  the  underlying  bone  and  finally  completely  destroyed.  The 
bone  beneath  the  destroyed  cartilage  may  become  involved 
secondarily.  The  tuberculous  process  may  extend  along  the 
ligaments  and  destroy  them.  Ultimately  there  is  destruction  of 
the  synovial  membrane,  cartilage,  and  articular  ends  of  the  bone, 
which  results  in  luxation  or  partial  dislocation.  The  synovial 
cavity  of  a  tuberculous  joint  contains  exudate  and  necrotic  tuber- 
cular tissue.     It  may  vary  from  serous  to  sero-purulent. 

Repair  :  If  the  tuberculous  process  cease,  granulation  tissue 
replaces  the  destroyed  tissue.  This  granulation  tissue  may  be 
transformed  into  fibrous  tissue,  and  produce  adhesions  between 
adjacent  joints  (fibrous  anchylosis).  Or  the  fibrous  tissue  may 
be  converted  (metaplasia)  into  cartilage  (cartilaginous  anchylo- 
sis). True  bone  may  form  in  the  cartilage  (bony  anchylosis). 
Generally  the  process  is  the  same  in  all  the  bones  and  joints. 
Certain  peculiarities  occur  in  bones  and  joints   of  special  regions. 


41 


Spine :  Tuberculous  disease  begins  in  the  marrow  of  the  ante- 
rior portion  of  the  body  of  the  vertebrae,  and  causes  tuberculous 
softening  of  the  affected  parts.  The  process  may  extend  forward 
and  beneath  the  prevertebral  ligaments.  In  that  way  the  body 
of  adjacent  vertebrae  are  involved.  As  the  vertebrse  soften,  the 
superincumbent  weight  causes  a  bending  forward  of  that  portion 
of  the  spine  above  the  disease,  and  an  angular  deformity  or 
"knuckle"  appears  in  the  back.  The  tubercular  process  may 
extend  to  the  soft  tissues  in  front  of  the  spine  and  produce  a 
tubercular  abscess  ("  cold  abscess").  If  the  disease  is  in  the 
cervical  region  this  abscess  may  project  into  the  pharynx  ("  ret- 
ropharyngeal abscess").  If  the  abscess  is  lower  it  may  extend 
into  the  pleural  cavity,  and  has  been  known  to  rupture  into  the 
lungs  or  large  vessels.  Or  the  abscess  may  first  appear  in  the 
back,  outside  of  the  quadratus  muscle  ("lumbar  abscess").  Or 
it  may  appear  in  the  ilio-psoas  region  ("iliac  abscess  ").  Such 
an  abscess  occasionally  ruptures  into  the  intestines.  Or  it  may 
extend  beneath  Poupart's  ligament  ("  femoral  abscess  "). 

Secondary  distortion  of  the  bones  due  to  malposition  and  pres- 
sure occurs.  It  is  said  that  alteration  in  the  diameters  of  the 
skull  occurs.  Deformities  of  the  ribs  and  thorax  are  common 
("pigeon  breast,"  etc.). 

Various  deformities  of  the  large  vessels  may  occur,  especially 
if  the  disease  arises  rather  late.  Deformities  are  due  to  the  fact 
the  spine  is  shortened,  while  the  blood  vessels  retain  their  length. 

Potf s  pufa/ysis  :  The  tuberculous  process  may  extend  back- 
wards through  the  bodies  of  the  vertebrae  to  the  spinal  dura. 
Tuberculous  granulations  may  surround  and  cause  pressure  upon 
the  spinal  cord.  Pressure  upon  the  cord  never  is  caused  by 
diminution  of  the  calibre  of  the  spinal  canal,  due  to  the  formation 
of  the  knuckle.  Occasionally  the  pressure  is  due  to  loose  frag- 
ments of  tuberculous  bone.  The  pressure  causes  paralysis  of  the 
cord  below  the  point  of  pressure  ("  Pott's  paralysis").  Destruc- 
tion of  the  cord  rarely  follows,  and  most  cases  of  Pott's  paralysis 
regain  complete  function. 

If  the  tubercular  process  cease  the  lost  tissue  is  replaced  by 
fibrous  tissue,  which  ultimately  may  be  converted  into  bone  and 
lead  to  a  more  or  less  complete  anchylosis  of  several  adjacent 
vertebrae.  In  these  cases  the  knuckle  becomes  rounded,  rather 
than  angular.  Large  abscesses  may  be  inspissated  or  absorbed, 
or  their  contents  may  become  calcified. 


42 


////.•  The  disease  begins  sometimes  in  ihc  ui)per  epiphysis  of 
tlie  femur,  very  fre(iuently  in  the  acetabulum.  If  it  begin  in  the 
epiphysis  it  usually  cxtentls  into  the  joint,  erodes  and  destroys 
the  head  of  the  femur.  The  acetabulum  is  softened,  and  under 
pressure  may  be  extended  upwards  ("  wandering  acetabulum  "). 
Extension  to  the  soft  tissues  and  formation  of  an  abscess  is  com- 
mon. If  the  acetabulum  is  the  primary  seat  of  the  disease 
destruction  of  the  joints  follows.  The  process,  however,  fre- 
quently extends  through  the  base  of  the  acetabulum,  and  an 
abscess  is  formed  within  the  pelvis.  Acetabular  disease,  as  a 
rule,  therefore,  is  much  more  serious  than  hip  disease,  which 
begins  in  the  epiphysis. 

If  the  head  of  the  femur  is  extensively  destroyed  partial  or 
complete  dislocation  of  the  head  of  the  bone  may  occur.  Occa- 
sionally the  process  causes  fracture  of  the  neck  of  the  femur. 
The  contraction  of  certain  muscles  leads  to  characteristic  deform- 
ity of  the  leg.  Often  early  shortening  of  the  leg  occurs  either 
from  partial  dislocation  or  from  failure  of  the  bone  to  develop  at 
the  usual  rate. 

Knee :  "  Tumor  Albus."  The  process  in  the  knee  may  begin 
in  any  of  the  bones  which  enter  into  the  knee  joint.  Primary 
disease  of  the  pctalla  is  not  uncommon.  Rarely  the  fibula  is 
primarily  affected.  The  destruction  of  the  joint  often  is  rapid, 
and  secondary  muscular  contraction  draws  the  lower  leg  u])ward 
(flexion),  outward,  and  backward.  Enormous  swelling  of  the 
knee  usually  occurs.     Abscesses  and  sinuses  are  common. 

Ankle  joint :  The  disease  may  begin  in  any  of  the  bones  of 
the  tarsus.  If  one  small  bone  is  affected  primarily  several  adja- 
cent small  bones  usually  are  involved,  so  that  extensive  destruc- 
tion is  required  to  remove  the  entire  process.  Abscess  and  sinus 
formation  is  common. 

Otiier  joints  :  The  wrist,  elbow,  and  shoulder  joints  are  less 
frequently  diseased  than  the  joints  of  the  leg,  but  are  not  uncom- 
mon. The  cranial  bones,  sternum,  clavicle,  and  ribs  are  affected 
still  less  often. 

(iross  appearances  :  "lione.  Recognition  of  the  limits  of  tuber- 
culous disease  at  the  time  of  operation  is  difficult.  The  bone 
may  show  either  more  or  less  extensive  cavities  filled  with  caseous 
material,  surrounded  by  purplish  granulation  tissue,  or  may  show 
softened  yellowish  masses  of  bone,  surrounded  by  granulation 
tissue.     Miliary  tubercles  seldom  can  be  recognized. 


43 


Joints  :  If  the  synovial  membrane  is  affected  it  sliows  at  first  a 
surface  studded  with  discrete  yellowish  or  whitish  circular  areas, 
somewhat  variable  in  size,  not  larger  than  the  head  of  a  pin.  If 
the  process  has  persisted  the  surface  of  the  synovial  membrane  is 
pitted  with  more  or  less  extensive  ulceration.  Occasionally  in 
the  joints  are  extensive  papillary  growths,  "  fungus  joints,"  com- 
posed of  tuberculous  tissue.  The  amount  of  fluid  in  the  joints  is 
variable — it  may  be  very  slight  ("caries  sicca"),  or  it  may  be 
large,  and  consist  of  cloudy  serum  ("hydrops"),  or  of  fluid, 
caseous  material  and  pus,  into  which  recent  or  remote  haimor- 
rhages  may  have  taken  place. 

Principles  of  treatment :  It  is  to  be  remembered  that  in  many 
cases  tuberculosis  of  bones  and  joints  is  a  self-limited  disease. 
To  favor  this  spontaneous  cure  of  the  disease  it  is  necessary  to 
keep  the  diseased  tissues  at  rest  and  protected.  This  is  accom- 
plished in  various  ways  in  different  parts  of  the  body.  Various 
braces  and  splints  are  employed,  e.g.,  Taylor  back  brace,  Taylor 
hip  splint,  Thomas  knee  splint,  etc.  In  some  cases  plaster  of 
Paris  splints  are  useful,  plaster  jackets,  etc.  In  other  cases  rest 
in  bed  with  fixation  is  employed  (Bradford  frame,  etc.).  The 
ideal  method  would  be  to  detect  the  tubercular  focus  while  it  is 
confined  to  the  bone,  by  the  X-ray,  and  to  excise  the  entire  af- 
fected area.  This  seldom  is  practicable.  In  many  cases  pallia- 
tive operations  are  indicated  on  general  surgical  grounds. 


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